Feb 10

Regifting Robin is a cool mind trick that can guess any two-digit number you imagine.

Go to Regiftable.com to play the game, then come back here for an explanation on how it’s done.  Though if you are a programmer, you should be able to easily figure it out for yourself.

The game asks you to select any two digit number (example 25).  Next, you are to subtract the both the first and second digits from your number (example: 25 – 2 – 5 = 18).  Then you are to select a gift from a grid of all possible answers.  In the final page, Regifting Robin correctly guesses your gift.  So how does this nifty trick work?

The equation can be represented as:  (10*x + y) – x – y = 9*x

Using our example, x = 2 and y = 5, so that’s (10*2 + 5) – 2 – 5 = 9*2 = 18.

In the gift grid, each 9*x box has the same gift, e.g., the boxes numbered 9, 18, 27, 36, etc. all are marked “Bath Salts.”

The selected gift is changed each time to make the trick seem more real.

Share and Enjoy:

Article published on February 10, 2009

### 164 Responses to “Regifting Robin Mind Trick”

1. Varmint Says:

This would work if you input any numbers into the system. Hoowever, if everything is done in you head, how does the system know what you have chosen and come back with the right answer.

2. Jesse Says:

Varmint, you clearly don’t understand what’s going on.

3. Linda Says:

simply said, and two digit number that you chose and subtract like that will end up a multiple of 9. All the multiples of 9 are the same gift, and changed each time so it seems like she’s reading your mind but it’s a trick. 🙂

4. Linda Says:

ANY two digit number. Sorry. 🙂

5. Jennifer Says:

I am glad I came here because I was completely stumped.!!LOL

6. el retardo Says:

OHHHHH!!!!!!!!!!!!!!!!!!!!!!!
i think i get it now but im not sure

7. Johanna Says:

ok you guys, i’m glad i found this page! haha so, to those of you who don’t understand, it’s a little complicated. here it goes:

my first number I chose was 24 so this is how it’s broken down

(10 x 2=20) then do 20+4=24 right

then do what they asked 24-2-4= 18

SO now 18/2=9 (18 devided by 2 equals 9)

How they guess YOUR ANSWER correctly, all of the game is based off of the numer 9, all of the multiples of 9= 9, 18, 27, 36, 45 etc. so the gifts just keep changing as you keep trying to figure it out! so basically 9 18 27 36 45 and so on, are all the same gifts, and they change everytime you try again. So when you use the formula that they gave to you 25-2-5 will end up in the multiples of 9. GET IT!!!

8. Carey Says:

i dont get it… i mean im sure it xplains it up there but im not good at math so i really dont get it

9. Johanna Says:

Carey, which numbers did you use?

10. Steve Says:

It doesn’t work if you go back and use the same number again. Test it out.

11. Steve Says:

Sorry about that…..if you choose a number that is not a multiple of 9 then it wont work.

12. Johanna Says:

well here’s the thing, go ahead and choose any 2 digit numbers, any random number, and they really do all end up with multiples of 9. I tried several numbers to see if they did, and they all did.

13. courtttttt Says:

hey oh my goshhh im only like 11 and totally stupidd hehe… soo.. i totallyy needed this websitee!!!! lol itss awesomee! i showed my friends and they were amazed and they are still tryin to figure out how it worksss but im so smartt i looked this upp soo yuuupp…. loll

ok for those of u that dont get it ….
this whole game works off of the number system 9 like multiples of 9 so it cud be ( 9,18, 24,36 etc.) and under the numbers listed aboce they all have the same presents and each round the presents keep changing lol soo yeah hope i helpeddd. (:

14. Varmint Says:

My bad. I missed the part of where they change the gifts each time.

15. Margaret Says:

The issue was confusing in the beginning because of the algebra explanation. Any two numbers you choose & do the subtraction for will always come up a multiple of 9. So, in the grid every multiple of 9 will have the same gift. Check that out. And every time you click on the URL, the gifts will change for every multiple of 9. Check out any other number on the grid that is not a multiple of 9 – her answer then, will be wrong, but you can’t do the required arithmetic without coming up with an answer of “a multiple of 9”.

16. Me Says:

how is this possible regardless of what 2 digit number you begin with that the addition of those 2 digits subtracted from the number as a whole will ALWAYS yield a multiple of 9??? what is the science behind that principal alone???

17. Greg Says:

There is no “science” really; just start plugging in numbers: [xy] = [xy] – x – y; 0 = 0, 1 = 0, 2 = 0, … , 10 = 9, 11 = 9, 12 = 9, …. , 20 = 18, 21 = 18, 22 = 18, … , 30 = 27, 21 = 27, 22 = 27, ….. , ……….. , 97 = 81, 98 = 81, 99 = 81.
Well, there probably is some math formula that could be derived that predicts what the result answers would be for numbers in number systems of other “bases”, ie base 8, base 16; but for the case of our base 10 number system, trial and error makes it clear — I don’t care that it’s multiples of 9 — they have the same gift item for all possible answers, so it wouldn’t matter what the numericals answers are. If there are only 10 answers for all numbers between 0 and 99, and they’ve got the same gift for all 10 possible answers, then they always “guess” it.
It’s a stupid “game” in my opinion.

Greg

18. Greg Says:

Correction to my post #17: The equation corresponding to the number question they ask you is better represented as: for a given 2-digit number [xy], [xy] – x – y = result
And in my example, after 30 = 27, it of course should read: 31 = 27, 32 = 27.

Greg

19. Johanna Says:

Post #16, like 17 said, there is no science behind. You should just try it out yourself, choose any number. With the formula that they are using, the number will always turn out to be a multiple of 9. try any number, wether it’s an even number like 42, it would be:

(10×4=40+2= 42) 42-4-2= 36 then with the 36, 9 goes into 36 four times

9×4=36 AGAIN A MULTIPLE OF 9

Let’s try another one

67

67-6-7=54 (formula

9×6= 54!!!! See!!!

Again, due to the formula that they are using, the number will always be a multiple of 9!! (10*x + y) – x – y = 9*x

20. theGrasp Says:

Johanna got it: the science behind it would be a proof that for any two digit integer (10a + b) the integer minus the values of the digits (10a + b) – a – b is equal to 9 and would go something like:

(10a + b) – a – b = x
10a + b – a – b = x
10a – a + b – b = x
10a – a = x
9a = x

qed: all values of x are an integer divisible by 9

But the real question is why did i get suspicious email from notify@visaonlinesecure.com moments after clicking on the link?

21. Johanna Says:

The Grasp, that i’m not sur? I never received an e-mail from them. Maybe it is just a advertisement? I have no idea? what did the e-mail say? I don’t want to click on it.

22. Robert Phelps Says:

You guys are to young, it’s based on casting out 9s a way to check math work all functions, look up “casting out nines”

23. Johanna Says:

Robert Phelps,

Who are you speaking too? Who is too young?

24. swimgod741 Says:

how does she know what numbers you are going to use though?

25. johanna Says:

swimgod741, she doesn’t know what numbers you will use. See because of that math formula, example 24-2-4 it will always be a multiple of 9. so all of the gifts that are a multiple of 9 will change every time you try the regifting again, so the first time let’s say you end up with the number 27, if you look at 9, 18, 27, 36, 45 and so forth, they all have the same gift. so every time you try again, the gift changes! Get it? 🙂

26. yes, but Says:

but all the gifts that are a multiple of 9 are NOT the same gift. so how do they know which multiple of 9 you are going to select? it has to be more than just a sheer guess, because you can try it over and over and she will guess it everytime.

27. dantheman Says:

yes but, check again all mults of 9 ARE the same 9,18,27,36,45,54,63,72,81,90,99. but its still kind cool

28. emilyjune Says:

this took forever to figure out.. but after reading your guy’s comments it makes sense. i didnt realize that ALL of the multiples of nine are the same gift. thats pretty cool. =]

29. Charlotte Says:

OK, how does she know if I’ve followed directions and chosen a number, done the match, etc. or not? Every time I did this, she was right. But then I tried not choosing a number, just clicking on next and “picking out” a gift. She of course didn’t get it right. I guess this supports the multiples of nine being the same gift.

30. dantheman Says:

Oh jeese, SHE dosent KNOW anything its a program.. it works if you follow the directions, if you dont follow directions it would just be luck if you guesed right. but if you didnt follow directions and got it right then you picked a multiple of 9 on accident

31. Ken Says:

What did not get explained in the explanation is this: Think place value. In any whole number, if you have one digit, that number represents the “ones”. If you have two digits, the right digit is the “ones” digit and the left one is the “tens” digit. For any two digit number, if you let “x” represent the left digit and “y” represent the right digit of your number, the the actual two digit number would be 10 times x plus y. (Example: if your number is 37, then x=3 and y=7. 10 times 3 is 30, plus 7 is 37.) When you subtract the individual digits from the original, you are starting with the original (10x + y) and subtracting each of the individual digits “x” and “y” from that. Hence the formula in the original explanation , 10x + y – x -y. Rules of arithmetic as well as algebra allow you to rewrite it as 10x – x +y -y if you wish. 10x -x = 9x. y-y=0, so when you select your number (any two digit number) and subtract the individual digits from it, by the rules of basic arithmetic and algebra you wind up with a number which is 9 times the left digit of your original number. That means that the number you look for on the grid will always be a multiple of 9. The program is written to change the items on the grid, but you will notice that all of the boxes with numbers that are multiples of 9 have the same thing in them. The program is writtten to do that. The illusion is based on you being focused on just the box with your number in it, and not really noticing that several other boxes have the same item listed. Shifting the items around each time you play contributes to the illusion.

32. Dr Jim Says:

Look at it another way. Each column represents the multiple of 9.
This first column (11 to 19) always yields 9
The second column (20 to 29) always yields 18
The third column (30 to 29) always yields 27… on to column 9 with 81
So gifts in position 9 and 18 and 27…. 81 are always the same.
To see this clearly, pick your number (any two digits) and look at the gifts in position 9 and 18 and 27…. 81 before you let Robin pick (which takes you to a page so you can’t track the number)

33. Barbara Says:

A bit more explanation about why the formula always works:

The formula appears as x-y-z=N (where N is a multiple of 9)
but the actual equation is: (10*x + y) – x – y = 9*x

In all cases, you really end up with y*10 minus y because you always subtract z, or the units position of the 2-digit number, which is really just getting you back to an even multiple of 10 in every case. So – you end up with a multiple of 10 minus the “number of 10’s” which is equivalent to subtracting 1 from 10 which always gives 9.

So for the multiples of 10: 10-1=9; 20-2=18; 30-3=27 etc.
And for any two-digit number, the units position never “matters” because you always subtract it !
25-2-5=18, or 25-5=20 -2 = 18
28-2-8=18, or 28-8=20 -2 = 18

10 – 1 = 9
up to 20= 9
up to 30= 18
up to 40= 27
etc

And if you look, you will see that all the multiples of 9 (9,18,27,36,etc) are the same picture. You don’t really have to worry about 1 since you are only supposed to use 2-digit numbers, so 10 is the smallest. So no matter what you pick, you get a multiple of 9. Since they always change the picture, you always think it’s different, but in reality, it’s not.

34. Bill Says:

I used the same number 3 times in a row and then changed it on the 4th time– and the program was correct each time. I noticed that STEVE said, on Feb. 20th that choosing the same number again didn’t work for him…..

35. Nicko Says:

ok dis is the trick
all the multiples of 9 are the same
eg. 9, 18, 27, 36 are all the same gift items.
if you choose a 2-digit number and subtract the two numbers from it it will always end up with a multiple of 9.
eg. 35( 35-3-5=27)
(dats just how maths is)
However every time you play the gifts changes- to make u tink dat she is reading your mind each time u play.
Get it!

36. Mark Says:

By the way, another way to look at this is that the program (or “Robin”)which selects your answer never tells you what number you actually used to begin with. What is really happening here is that of a mathematical compliment scenario where no matter which number you select, the result is narrowed down to just a few possibilities (either: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, or 99) and all of those numbers have the same gift item associated with it on each run of the program. Thus, the numbers don’t change, but rather, the gift associated with those numbers changes each and every time. The appearance of a “magic trick” is that we tend to assume that Robin knows what number we selected to begin with when we see the answer of the gift she (or the program) has selected. But the reality is that she only knows that your result is just one of those results, but has no idea which one of them is your result after subtraction. If you now play the game again, be sure to look at the matrix and find those numbers I just mentioned… they will all have the same gift or prize associated with them, whereas the rest of the matrix may have other gifts randomly assigned to the other numbers.

37. Marty Says:

Mark has it right. Here’s a abreviated explination: There is only one answer each time she scrambles the prizes. When you subtract both digits of a two digit number from 11-99 you always end up with a multiple of 9. i.e. 9 18 27 36 45 54 63 72 81 (I didn’t know that) Therefore she just rotates the prize around each time to one of those numbers and always gets it right. At any rate, pretty cool……..

38. phil Says:

Y’all have too much time on your hands. 🙂

39. baxter Says:

easy way, take the # 99- 9-9= 81, take 98-9-8=81, take 97-9-7=81, see the pattern first, all # from 99 to 90 will equal 81, bath salts is in the box is 81,
Take 89-8-9= 72, 88 – 8-8= 72, 87 – 8- 7=72, note the pattern, all # from 89 to 80 will equal 72, balths salts is in the box 72 and 81,
All # from 79 to 70 will equal 63, bath salts is in the box 81-72 and 63.
All # from 69 to 60 will equal 54,
bath salts is in the box 81 & 72 & 63 & 54
this pattern will continue

40. trickster Says:

Bottom line question. There are several gifts. Although there is a mathematical formula to get multiples of 9, there is no explanation of why it doesn’t always come up the same item. Sure the items change to add to the mystery, but nevertheless the “gift” always matches your match. Can someone explain why the “changing gift” always matches your answer?
OK. I just looked at the pop up again. I have been assuming here that the gifts are always on the same squares. –They are not.–
Herein lies the trick.
The gifts change squares every time, but identicle gifts Always land on a multiple of nine. When your number changes, whether the gift changes or not, it is still a multiple of 9.
Due to the nature of the visuals, you don’t really get that the squares keep changing since you are always looking for your gift among the mass of other gifts.
Rather than look at this as an equation lets just look at it logically.
So lets simplyfy this, and pretend I’m the lady:
Forget the math just pick a multiple of 9.
OK got it?
Now I’m putting up ONLY 9 squares up with a multiple of 9 on each, with the same gift on all of them. A toaster.
Now pick your number and it will have a gift on it, it doesn’t matter which number really, they’re all the same gift. They’re all “A toaster”.
Now I will pretend to guess…Great! Your gift is A toaster right?
Try it again. This time I will change the gift to a pair of socks, but of course we will still use only 9 squares that are a multiple of 9 with a pair of socks on all.
Pretending to guess…Great! I guessed a pair of socks! Am I right again!
Doesn’t seem so tricky now does it?
Throw in a mathmatical equation that always has the same 9 sets of answers, make all 9 sets the same gift, Add a mass of other gifts with letters and graphics that all seem to blend together. Presto I’m a web sensation!

41. James Says:

The main basis of this trick has now been explained (several times 🙂 I’d just like to add a small part of the finesse that hasn’t been mentioned. Since one’s natural tendency, when trying the robin again, is to use a DIFFERENT number each time, and therefore you get a DIFFERENT multiple of nine each time – you don’t notice that in fact ALL the multiples of nine have a different gift.

42. Robb Says:

Forget how the equation to arrive at multiples of 9 works.
All you need to know is, ather the basic sum is performed only one of thes numbers will be returned. 9,18,27,36,45,54,63,72,81,90,99.
eachtime you run the progam these numbers will all have the same gift displayed. Try it.

43. Robb Says:

Forget how the equation to arrive at multiples of 9 works.
All you need to know is, after the basic sum is performed only one of thes numbers will be returned. 9,18,27,36,45,54,63,72,81,90,99.
eachtime you run the progam these numbers will all have the same gift displayed. Try it.

Like boring now…..

Guys i NEED a pain pill. I got a headache from all this stuff.

46. Terry Says:

As many of the comments show, we are a nation of math illiterates. And these people (presumably) vote. Scary.

In reply to Terry; you must think you are smart…hahaha..

48. Calc Says:

For those still confused do this simple test:
1) Click into the gift screen (do not pick a number first).
2) Look at box #90 EVERY time and remember the gift.
3) Click through for the answer. It WILL be the gift in box #90 everytime.

You can amaze your friends if you have them at the screen and YOU can

If you don’t want to use box #90, use #27, #9, #36 if you like.

Did you notice box #90, #27, and #9 are always the same and ALWAYS

Making sense now?

49. bazookamimi Says:

@Charlotte: yes that’s exactly how I figured it out – picking a random number without doing the math first & it was wrong. So I realized it’s the math that makes it work, THEN realized no matter what number I started with there were only 9 possible results and that’s when the lightbulb went on…

But I was totally stumped for about 5 minutes & so was my husband =) it was weird for a minute when we were both doing different numbers and “she” was getting them both “right”

50. Sonjia Says:

okay i really dont get this. she didn’t even get it right..
someone tell me whats teh point of the calculator…

51. Sonjia is a morooon Says:

Sonjia you are a damn moron..

52. maria Says:

every time it comes out a multiple of 9 and all the multiple of 9’s are the same
if you just pick a number on the chart and don’t subtract it, it’ll get the multiple of 9 gift it took me a wile to figure out it and i had some help from reading these comments
thanks,
peace out

53. david Says:

Don’t pick a number or do any math and Robin will still pick your “choice”….

54. happy new year Says:

Hey kids suprise suprise. its the number your mouse pointer is hovering on. it just that simple. dont do any math just try it. when you do the equation it puts a number in your head. Automatically you bring the mouse pointer to that number, the program reads this and voila! no math or huge multiples of nine equations or anything.

55. Michael W. Reece Says:

Well, my dears, it’s not all that complicated, really … just a little trick with numbers. Let me explain.

First, there are 99 numbers in the “second” box (one can only use “2-digit” numbers and so one is limited to using numbers from 10 – 99, which simplifies the problem for the puzzle writer, although if the “second box” was limited to that range there wouldn’t be 99 boxes, as I’ll explain below), yes? And each number has a “gift” associated with it. Further, whoever thought this up knows that, in the minds of the game players, the “gifts” will be thought to be distributed randomly within the 99 squares (Sort of “natural” psychology). And nothing could be further from the truth. That’s because in the range of numbers running from 10-99, there are only nine possible outcomes when one subtracts the two digits of the number selected from the original number: 9, 18, 27, 36, 45, 54, 63, 72 and 81. You will notice that each of those nine numbers is exactly 9 more than the previous number. And that’s not coincidental. Allow me to provide an example: if the number you pick is, say, 25, then 25-2-5=18. Then, if you check to see what happens when you pick 35, the result is 35-3-5=27, which is nine more than the 18 you would get if you had picked 25 in the first place. Now, the same holds true for each of the ten point ranges in the range of 10-99. That is, as you move from the 20’s to the 30’s to the 40’s the result of subtracting the two numbers from the original will (1) always be a number that is nine greater than it was for the previous 10-point series, and (2) that number is the same throughout each 10-point series you have chosen (in the range from 20-29, e.g., subtracting the two digits from the original number will always total the number 18, throughout the entire range).

So. Once you “pick” a number, whoever thought up this little puzzle knows you have chosen one of only nine possible outcomes (9, 18, 27, 36, 45, 54, 63, 72 or 81, one for each of the ten-point ranges). And since he asks “you” what your ultimate number is, and points you to that little box with the “gift” in it (And he already “knows” what your number is because of what I wrote above. That is, if you pick 20-something the result is 18, if you pick 30-something the result is 27, and so on.) then you are led to believe that there is something mystical going on here. But, as I hope I have demonstrated, no mystery here.

And the reason the “puzzler” does not allow any single-digit numbers is because for any number from 0-9, subtracting that number from the original number will always result in a “0”, and the puzzle would be much easier to figure out! Therefore, the first 9 boxes of the 99 boxes are irrelevant, but they tend to add to the mystery.

There. I hope I have been able to erase any “unbelievable” aspects to this conundrum. Numbers is numbers and people can do all kinds of tricky things with them like, er, the government.

56. Joe Says:

HERE IS THE ANSWER!!!!!! NO MATH, NO FORMULAS!!!!

IF YOU LOOK AT THE CHART, ALL THE MULTIPLES OF 9 ARE THE SAME OBJECT!!!

Example: 9,18,27,36,45,54,63,72,81… are all Oven Mitt or Ref. Magnet or whatever. None of the other numbers matter at all. Those will always be the same

1. if you subtract a 2 digit number by itself it is always a multiple of 9

2. every single time you go to match up your number look at the others as well (undoubtly all the other multiples will be the same object as well)

57. Dale Says:

Any two digit number, say 41, minus the digits that make the number, 41-4-1, will always equal a multiple of 9. Example:
41-4-1=36
42-4-2=36
43-4-3=36
44-4-3=36 (All Multiples of 9)
45-4-5=36
46-4-6=36
Try any number
75-7-5=63 Multiple of 9

Now since Robin knows you have to calculate a multiple of 9, all the gifts that are in the numbers 9,18,27,36,45,54,63………
Are all the same gift. They just change the multiple of 9 gifts each time
you play, but they are all the same gift for that play.
Try the game again and watch the gifts under these numbers

58. Robin Says:

It also work for the number 100!

59. DOC Says:

There are lots of odd number patterns , check this out!!!
Tell someone that you can square any 2 digit number ending in 5 in your head faster then they can on a calculator!! Howz it work ya say??
Example
25 x 25 = 625 go ahead and check that with your calculator

any 2 digit number ending in 5 squared will ALWAYS have 25 as the last 2 digits. To get the first digt or digits
take the first digit of the original number , in the above example that would be 2
now add 1 to the first digit, in the above example that would be 3
now multiply those digits together , in the above example
that would be 2×3 which equals 6
Put that digit in front of the 25 and you have 625 which is the correct answer!!

It works from 15 to 95 quick and easy. It actually works on all digits that end in 5 but of course becomes more complicated beyond 2 digits. The principle does still work however.
Once you get the concept you can literally do the equation in your head faster then someone can with a calculator!!

I stumped my math teacher with that in the 6th grade about 1000 years ago!! LOL

60. koolkay Says:

61. Harry L. Hall Says:

What happened, Robin, You missed three in a row!

62. Mike Long Says:

10 is 10-1-0 = 9
11 is 11-1-1=9
12 is 12-1-2=9

23 is 23-2-3=18

so no matter the 2 digit number you pick you will ALWAYS end up with an answer that is a power of 9 meaning that these numbers will ALL HAVE THE SAME GIFT IN IT:
9
18
27
36
45
63
72
81
90
99

63. Babs Says:

Hey fellow slow nerds… here’s an easy explanation. The formula that is given to you will ALWAYS give you a number that is a multiple of 9. Each box that is a multiple of 9 is the same gift. If you don’t follow the formula and guess a random number that is not a multiple of 9 then our little Ms. Robin will guess incorrectly. Regift that b#@\$%!

64. rick Says:

thanks for the explanation! it was driving me crazy

65. Braminator Says:

The math thing is a clever trick. What I had to realize was that each time the page ‘renews’ there will be a different gift in the 9-18-27, boxes. It switches it around. Haha, untill you actually look at it, it happens seemingly fluidlike. Lol

66. todd Says:

I cannot believe the number of people that could not understand how this is done. I mean sure, many people have a hard time with algebra, but the frigging 9 times tables??? How can anyone get the answer to how it is done, then try it again and still not understand how easy it is.

67. Jim Says:

Try using the number 66 ad see what happens.

68. Jimmmbers Says:

Wow. Idiots.

69. Lilu Says:

I think our future is not so bright after all. I love the guy that says that it’s where your mouse is hovering. It’s been explained perfectly a ga-zillion times, and there’s still people who can’t figure out how “she knows”. And somebody said something about why they need a calculator? I think you probably need a guided tour to get to work/school/the chicken plucking factory.

70. BOBBY Says:

WHAT GOOD IS ALGEBA ANY WAY IM 60 PLUS YEARS OLD AND I CANT SAY IT EVER PUT ANY MONEY IN MY HANDS

71. BOBBY Says:

WHAT GOOD IS ALGEBA ANY HOW? IM 60 PLUS YEARS OLD AND IT HAS NEVER PUT ANY MONEY IN MY HANDS

72. Ambrose Says:

Sorry to have to say this, but it also works with 3, 4, or as many digits as you want

73. seattlemkh Says:

Bobby, algebra (and trigonometry, and calculus, and linear algebra, and differential equations) put a lot of money into my hands, and allowed me to do some amazing things (like take a dive to 3000m in the Alvin research sub and drive around in the mud at the bottom of the ocean, for example). We need science and math people in a big way. Don’t knock it.

Secret: every 9th box is the same. Your choice will be a multiple of 9. One of those boxes is the answer to what you picked, and they’re all the same so it doesn’t matter what you picked.

74. sola Says:

Hahaha! I enjoyed the game and it was fun doing it over and over to see if the game would be wrong. It was like it was really reading your mind! The scientific explanation took the fun away. but MATH ROCKS!!!

75. Kim Says:

For clarification, since some people are still confused:

This chart shows all possible responses for any 2 digit number. Note that each answer is a multiple of 9.

10 – 1 – 0 = 9
11 – 1 – 1 = 9
12 – 1 – 2 = 9
13 – 1 – 3 = 9
14 – 1 – 4 = 9
15 – 1 – 5 = 9
16 – 1 – 6 = 9
17 – 1 – 7 = 9
18 – 1 – 8 = 9
19 – 1 – 9 = 9
20 – 2 – 0 = 18
21 – 2 – 1 = 18
22 – 2 – 2 = 18
23 – 2 – 3 = 18
24 – 2 – 4 = 18
25 – 2 – 5 = 18
26 – 2 – 6 = 18
27 – 2 – 7 = 18
28 – 2 – 8 = 18
29 – 2 – 9 = 18
30 – 3 – 0 = 27
31 – 3 – 1 = 27
32 – 3 – 2 = 27
33 – 3 – 3 = 27
34 – 3 – 4 = 27
35 – 3 – 5 = 27
36 – 3 – 6 = 27
37 – 3 – 7 = 27
38 – 3 – 8 = 27
39 – 3 – 9 = 27
40 – 4 – 0 = 36
41 – 4 – 1 = 36
42 – 4 – 2 = 36
43 – 4 – 3 = 36
44 – 4 – 4 = 36
45 – 4 – 5 = 36
46 – 4 – 6 = 36
47 – 4 – 7 = 36
48 – 4 – 8 = 36
49 – 4 – 9 = 36
50 – 5 – 0 = 45
51 – 5 – 1 = 45
52 – 5 – 2 = 45
53 – 5 – 3 = 45
54 – 5 – 4 = 45
55 – 5 – 5 = 45
56 – 5 – 6 = 45
57 – 5 – 7 = 45
58 – 5 – 8 = 45
59 – 5 – 9 = 45
60 – 6 – 0 = 54
61 – 6 – 1 = 54
62 – 6 – 2 = 54
63 – 6 – 3 = 54
64 – 6 – 4 = 54
65 – 6 – 5 = 54
66 – 6 – 6 = 54
67 – 6 – 7 = 54
68 – 6 – 8 = 54
69 – 6 – 9 = 54
70 – 7 – 0 = 63
71 – 7 – 1 = 63
72 – 7 – 2 = 63
73 – 7 – 3 = 63
74 – 7 – 4 = 63
75 – 7 – 5 = 63
76 – 7 – 6 = 63
77 – 7 – 7 = 63
78 – 7 – 8 = 63
79 – 7 – 9 = 63
80 – 8 – 0 = 72
81 – 8 – 1 = 72
82 – 8 – 2 = 72
83 – 8 – 3 = 72
84 – 8 – 4 = 72
85 – 8 – 5 = 72
86 – 8 – 6 = 72
87 – 8 – 7 = 72
88 – 8 – 8 = 72
89 – 8 – 9 = 72
90 – 9 – 0 = 81
91 – 9 – 1 = 81
92 – 9 – 2 = 81
93 – 9 – 3 = 81
94 – 9 – 4 = 81
95 – 9 – 5 = 81
96 – 9 – 6 = 81
97 – 9 – 7 = 81
98 – 9 – 8 = 81
99 – 9 – 9 = 81

The algebraic expression given above shows WHY this works: you’re basically asking the person to choose the x & y values and due to the wonderful reliability & predictability of math, it always works!!

76. Calvin Massey Says:

A very, very good math trick!!!!!

77. Kamloopser Says:

HERE’S AN EXPLANATION OF WHY WE ALWAYS GET A MULTIPLE OF 9.
If you take off the right digit first you’ll always get a multiple of 10. ( for example 37 – 7 = 30)
When you then take off the left hand digit you will then change it to a multiple of 9 ( in this example 30 which is 3 x 10 minus 3 reduces it to 3 x 9 which is 27)

78. Lindy S. Monteith Says:

in the grid with all the object/gifts, why do they include all of the one digit numbers lower than 9?
i understand why they included 9 because if some one chose 10 as their original number, 9 would be the outcome.
but why did they include anything lower than 9? just to make it more interesting/confusing?
anything 1-8 is an impossible outcome isn’t it?
because any one chose anything below 10 as their starting number would receive zero as their outcome.

79. Calvin Massey Says:

To Lindy S. Monteith,

You are correct on the digits 1 thru 8. Also, they included 82 thru 99 just to confuse us. Anything above 81 is also an impossible outcome, isn’t it.

80. Lindy S. Monteith Says:

To Calvin,

Yes, I think they did include the digits 82-99 to confuse us.
Since 99 is obviously the highest two digit number, it would give you the highest possible outcome…. right?
I think so because, if you “plug in” 99 into the equation, you receive 81 as your answer…

(10x + y) – x – y = 9x

if X=9 and y=9
then…

(90 + 9) – 9 – 9 = 81

81. Calvin Massey Says:

To Lindy,

I believe you love math like I do. Here’s a math problem you may like.
Pick any 5 digit number, then compose another number from those same 5 digits. Place the larger number on top and subtract the smaller number from the larger number. Circle 1 digit in the answer. Do not circle a zero as it is already a circle.
Send me the other digits in the answer in any order and I will tell you your circled number.

Calvin

82. Michael Says:

Simplified:

Any two-digit number subtracting both digits from the whole will always give a number divisible by 9.

If one looks at the matrix full of regifts, every number divisible by 9 has the SAME regift. The trick with the software is that at each attempt, the regifts are re-orientated.

Say from ‘label-maker’ to another one. Each time one accesses the program, the matrix swaps the regifts around, and it is fail-safe!

LOVELY math trick.

But it’s the MATRIX one needs to keep an eye on.

It’s doddle after that.

Cute.

83. Lindy Says:

Calvin Massey :
okay, so I picked a 5 digit number, rearanged the digits, and then subtracted the smaller number from the larger.
I recieved a 5 digit number, circled one digit, and was left with 4 numbers.
They were 5, 7, 6, and 5…did I do it right?

Lindy

84. Calvin Massey Says:

To Lindy,

You did follow directions and did it right, if your subtracting is correct.
Being a real mind reader, I caan see that you circled a 4 in your answer. This is in reply to your e-mail of Aug. ll, 2009. So be careful of what you think about because I can read minds.

85. HUONG LUPINOS Says:

This is the easiest way to figure out how “Regifting game” works: all you need to know the answer of Robin answer will be, is, just look at the number 81 on the Chart , then, any numbers that you come up with, will be the same Gift’s name. Do you get it?

Today i came to know that there are a lot of people in our ‘small world’ who have an empty skull!!!
What a shocking thing!!!

87. kate Says:

So, how do you build your own version of this?

88. allison Says:

ok all yall are dumb.the trick to this game is not multipals of 9 or any of that crap. have u ever tryed clikeing on the box with ur number and item in it! it is just were ever ur mouse is! im blond and 12 and i figured tat out!!!

89. John B. Says:

A simpler way to put it: no matter what 2-digit number you choose, from 10 to 99, there are only 9 possible answers. The grid has the same “gift” on each of those 9 numbers so you HAVE to “choose” the gift that she says you did (as the full list that somebody posted above shows).

90. chessspy Says:

I liked this trick. I’m 60 also, and know about ‘casting out the 9s and stuff like that. but it was the substitution each time that fooled me for a few minutes.
It’s a neat bit of code, and I admire people who can use the internet for fun things like this.
BTW, I bet I can guess which pattern of chess set you will use in a chess club! (Staunton pattern, am I right?)
Best
Alan D (chessspy) http://www.chessspy.co.uk

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92. Hydraulic Valves Says:

It’s a interesting test.

93. Teresa Says:

GEEZ I HATE MATH!!!!!!!!
If anyone ever sends me something like this again,I`m going to send them a virus!!!!!

94. Ricky T Says:

People, people! You just don’t get it, do you? This is a government sponsored puzzle. The feds are testing a new breakthrough in reverse computer engineering. The government has figured out how to use your display screen to “see” you. Using stealth waves emitted by your display screen, they detect where your eyes focus on your screen and the nice lady “guesses” your gift. The only way to stop this invasion of privacy is to where very dark sunglasses when viewing the screen. For \$50, I’ll give you other techniques to keep the fed out of your personal life. And, while we’re at it, you people need to learn the proper use of your and you’re. No charge for that advice.

95. maasamova Says:

Took me all of three minutes to figure out that subtracting the numbers from any two digit number will give you a number with a multiple of 9.

96. JamieD Says:

Ricky T

Quality!

97. Me2 Says:

Its Simple:
ANY 2 digit number – its digits = multiple of 9

eg. 56 – 5 – 6 = 45
Can 9 go into 45? Yes.
to prove it heres another
72 – 7 – 2 = 63
Can 9 go into 63? Yes.
Look at the jobs page and you’ll see all the multiples of 9 are the same job. No mind-reading there!

98. bex Says:

Its number 9 everytime (:

99. auntie Says:

Todd, times tables are not taught until 3rd grade.

100. auntie Says:

Ricky T, you misspelled wear.

101. auntie Says:

Allison, it’s 10:59 p.m., you’re 12, go to bed.

102. RickyT Says:

auntie, you are correct. First poster to catch it.

103. RodN Says:

Using the communitive property of subtraction (it doesn’t matter which order you do 2 subtractions) do the math the other way and you can see the trick happening.
99 – 9 = 90 – 9 = 81
98 – 8 = 90 – 9 = 81
97 – 7 = 90 – 9 = 81

and so on.

And if you are going to say there is no communitive property for subtraction, technically you are correct, you can’t swap which number is subtracted from the other and get the same answer 99-9 != 9-99

104. megan Says:

i have noticed that because the grid ends- 11, 22, 33, 44, 55, 66, 77, 88, and 99 do NOT work. She guesses wrong EVERY TIME! This trick kept me guessing all day. then i found this website 🙂

105. Meggie Says:

can u tell me that in english?

106. Meggie Says:

My teacher wonts us to know can u tell me some way i will know?
cuz i don’t get it.

HELP!!!!!!!

ha ha ha

108. Randunu Kumara Says:

Not only any 2 digits numbers, if you take any number and deduct all digits from orginal number answer is always a multiple of 9. This is the theory behind this. You can make lot of games to drive people crazy using this theory

109. umm you dont need to know this Says:

ok, i think that i am just really bad at math so i just believed what every one said soo nevermind

ok then umm you dont need to know this
im a modeler!!!!

111. Jimmy DuCaralho Says:

Quit over complicating things braniacs. I aint good at maths either, so I used good old excel to figure it out

It’s as simple as this: Due to some strange quirk of mathematics when you subtract both the first and second digits from ANY 2 digit number, from 10 to 99, the result is ALWAYS a multiple of 9. The only possibilities are 9,18, 27, 36, 45, 54, 63, 72 & 81

Now, if you look at the table on the website, you’ll see the all the multiples of 9 have the same name in them, which is the name she thinks of. Simple as that

112. Bethan Morley Says:

we were doung this in school we had to try and work out the rule in maths and it was a nightmare everyone was hipmatised by it then we worked out that if you take a 2 digit number for example 90-9-0=81 and that is a multiple of 9

it is easy when you think about it

113. The Truth Says:

For all of you that don’t or can’t understand, I offer The Truth. Regifting Robin is the devil and can read your thoughts. Now that you have played her game she owns you; you are in her control. Do not fall prey to those who mock you with numbers and symbols under the guize of a mathematical explanation, they are just members of the minions. Lock you doors and close your blinds, turn off your computer and unplug it, and don’t even think of using it again. You will thank me, oh yes.

114. insightcableman Says:

I figured it out on the first try. Here’s how: I picked three numbers at the same time and wrote them down on a piece of paper. I followed the instructions and did the math on paper for all three numbers. When it came time for me to “focus”, I was busy noticing that all of my answers had something in common, namely the number 9. NOTE: you can use this “Code breaker” on any type of magic or illusion trick.

115. Morpheus Says:

Let me tell you why you’re here. You’re here because you know something. What you know you can’t explain, but you feel it. You’ve felt it your entire life, that there’s something wrong with the world. You don’t know what it is, but it’s there, like a splinter in your mind, driving you mad. It is this feeling that has brought you here. The answer is out there, and it’s looking for you, and it will find you if you want it to. Here is the real and horrifying reality of just how Regifting Ronin is able to read your thoughts. She is simply a sentient program that can move in and out of any software still hard-wired to the system, the system you are a prisoner of.You are a slave, like everyone else, you were born into bondage, born inside a prison that you cannot smell, taste, or touch. A prison for your mind. The Matrix is everywhere, it is all around us. You can see it when you look out your window, or when you turn on your television. You can feel it when you go to work, or when go to church or when you pay your taxes. It is the world that has been pulled over your eyes to blind you from the truth. There are fields, endless fields where human beings are no longer born. We are grown. For the longest time, I wouldn’t believe it. And then I saw the fields with my own eyes, watched them liquefy the dead so they could be fed intravenously to the living. And standing there, facing the pure horrifying precision, I came to realize the obviousness of the truth.
I imagine that right now, you’re feeling a bit like Alice. Hm? Tumbling down the rabbit hole? You take the blue pill, the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill, you stay in Wonderland, and I show you how deep the rabbit hole goes.
Hope this helps.

116. Livy Says:

Morpheus, what the heck are you talking about?????

117. Morpheus Says:

I think I pretty much summed it up above. Take the red pill, coppertop.

118. freya Says:

it is a mind shanging thing that ends up having a really simple solushion,it is always in the 9 times tables

119. jetboy Says:

This is the most ridiculous thread I have ever read. Common sense, says it is a naturally recurring trick. If after the 2’nd or 3’rd time you played the game, you did not figure out your answer was always a multiple of 9, maybe you could have just scanned the board to see what other numbers had the same gift. I am glad that I am not the engineer type, because if you cant just see the basic trick easily, please don’t take flying lessons. The rest of the unsuspecting public that you are flying over doesn’t need you to crash the plane because you cant figure out why there is a mathematical anomaly. It just is. Sort it out and fix problem Einstein.

120. Mickey Finn Says:

Feel the shake, feel the earth quake.

121. Holly (: Says:

she got this rong over four times with me if you ask me this games a load of poop, 😀

122. Holly (: Says:

this game is a load of crapp,
seriously you guys are wasting your time
playing this ‘game’ 🙂

123. Obviously Says:

Holly (: is unable to do math. That is the ONLY way The game could get it “rong”. Follow the directions, and do the SIMPLE math correctly, and the game will “guess” it right EVERY time. Really.

124. RickyT Says:

Holly (: is obviously dyslexic (frowning face emoticon symbols are backwards), so go easy on her.

125. Obviously Says:

I am sorry, Holly. Thanks RickyT, I will be more compassionate in the future.

126. ME Says:

i know the trick, they are all multiples of nine. every time you do that to a two-digit number, it ends up as a multiple of nine. and if you look closely, all the 9 multiples are the same thing every time, they just mix up the names of what they are every time.

127. guy Says:

AHA! its so obvious now!!!!

128. Work this out? - TeakDoor.com - The Thailand Forum Says:

[…] Salts.” The selected gift is changed each time to make the trick seem more real. From here: Regifting Robin Mind Trick /or something like that __________________ bibo ergo […]

129. Apeke Says:

Here is the solution in laymen’s terms..
if you pick a number in the 90s the result is always going to be 81, any in the 80s it’ll be 72, any in the 70’s is 63, the pattern continues so when you get to the page listing the gifts, look at the gifts on 9, 18, 27, 36, 45, 54, 63, 72, and 81.

130. mballz rhari Says:

omfg how did it take me so long to realize this silly trick.
then i saw all multiples of 9- 9,18,27,36,45,54,63,72 all had same gifts.
and any number you pick WILL BE a multiple of 9 lol.

131. william young Says:

this silly trick is a multiple of nine

132. NIkky Says:

even if its a multiple of nine she still has to know the one i picked out of all them. so it still doesnt make sense.

133. Rolling Eyes Says:

Nikky, every multiple of nine is the same gift. Go read the comments, and pay attention this time. Then go play the game, and be mindful there also.

134. canyn Says:

There’s more than one way to skin a cat….

I MAY have missed this in the posts above, but I have yet to see the puzzle explained like this:

FORGET the units digit (the digit on the right in the 10º place). It has no effect on the outcome because according the ‘the rules’ you subtract it…it’s taken off the total, so it’s extraneous info thrown in to confuse.

What you end up with, then, is ALWAYS a single-digit number x 10:

10
20
30
40
.
.
90

ANY time you subtract the multiple of 10 FROM that number, the result is a multiple of 9.

40-4=36 ..a multiple of 9
50-5=45 ..a multiple of 9

WHY a multiple of 9? Because you are subtracting ‘1’ from every ‘ten’!

40 is four tens. When you subtract ‘4’ from that number..you are subtracting ONE from every TEN.

…it’s always going to be a multiple of 9.

It’s not hard to understand why 10 – 1 = 9, right? That’s exactly what you’re doing when you follow ‘the rules’ of this game.

The units digit kind does cloud the issue..and it’s useless, has no impact on the puzzle.

Ha! I did wonder at first how come my PC firewall was letting my mouse co-ordinates out.

Neat!

135. canyn Says:

‘The units digit kind does cloud the issue’

The units digit kind’a does cloud the issue…’

136. Kiki Says:

I still dont understand anything!!!! How could anyone understand those hard math equations!!!!! Oh well this trick is fun anyway

137. Ayush Says:

@kiki
you dont need to understand the equations…
see to crack it… dont do the maths…just start and look for all multiples of 9,
to understand it better choose the same no. they just change the gifts…

138. Dejan Says:

Hehehehehe, this was the first C program I did all by myself years ago. 😀

139. Manny Says:

Have noticed if u dont even try the number will be 99

140. =] Says:

All of you are wrong , there is no mathematical formula . . . . Regifting Robin is a magic psychic lady.

141. sv_rfi Says:

hmmm.. it’s a simple trick.. but very nice one… that simple math always result in the multiple of 9 and every time the symbol associated with 9,18,27,36,45…. changes.. and what it contains is the answer…

142. mark Says:

Each nuber has a differant gift. No math can explain what gift goes with your number you picked.
You eye iris diolates when you look at your answer. A camera is behind it all thats unseen by you. It notes your iris and pulls up your gift. Spi camera with out you knowlage. Hi tect stuff.

143. Sara Says:

Bahahahahha! Love it Mark.

144. austynluv333 Says:

lol:):):):)

Cool!

146. Jane Says:

Hey there!! I looked you up after I figured it boiled down to multiples of 9 but was still stumped. Thanks for helping me crack this number riddle!

147. Marto Says:

I never realised how many dopes there are on the planet.
All answers are products of 9, and all gifts in the list which are products of 9 are identical. Duuuuuuuuuuuuuuh

148. DanTheMan Says:

I last looked at this 03/09, the regifting trick is fun. The most fun is reading all the peoples comments. like” its where your mouse is hovering” hahaha, or “she got it wrong”. What a crack up, people explain how it works 100 different ways and some people still cant get it..
Let me explain it again, its magic… Real David Copperfield magic, dont try to figure it out or Robin will come looking for you..

if you pick “15”

15 – 5 – 1 = 9

the basic formula if you are restricted to picking two digits say “xy” is:

“xy” = x*10 + y (where * is the symbol for multiplication)
example:
96 = 90 + 6

Then subtracting as they say:

“xy” – x – y
= (x*10 + y) – x – y
= x * 9

meaning it doesn’t matter what “y” is actually, answer is always 9 times “x”

since x = 1 to 9 (can’t be 0 since then wouldn’t be “two digit” number)

(9 * x) can be only:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99

The webpage lists a grid of 11 x 9 i.e. 99 answers (mainly to hide the ONLY 9 possible answers in a wider sea of answers to give a semblance of “huge sea of potential answers”)

Looking up the “(9 * x)” numbers:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99

on the webpage you can see they ALL are associated with the SAME gift

What makes the trick hard to decipher on superficial examination when done repeatedly is that the the webpage generates labels dynamically so one time it may assign “Bath Salts” to the numbers:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99

While the next time you try it it may assign it “Happy Face Mug”.

It is this last step which makes probably removes the aspect of repeatability (which would be present if it was a book) – and on quick scan it may be hard to see a pattern in the 11 x 9 grid on screen.

150. Morpheous Says:

“answer” is trying to cover up the obvious, that Regifting Robin is a minion of Lucipher and is reading your mind. Forget all his fancy numbers, he is only trying to lull you into her submission.

151. Bob Says:

Great explanation of how it works…

Thanks
Bob

152. ozzie Says:

One problem with this … the game says “pick any two digit number …”. If i pick the number “11” this does not work because after you subtract the two single digits of “1” and “1” the end result is “0” and that digit is not in the next table.

153. Morpheous Says:

@ ozzie: Dumbaz, 11-1-1=9, not 0. Go find a preschool and sit in on a math lesson.

154. Amazed Says:

I’m amazed at the difficulty people have grasping this concept. I will admit that I ran through the game a few times before I realized that every number I chose was a multiple of 9…Beautiful in it’s simplicity and design

155. ZOMBEH Says:

Two explanations:
1. The Awesome One:
Morpehus was close to the answer, but a bit off. First of all, Robin is real, and she lives in the alternate flux field of reality. Imagine Reality as a stream and imagine a small ripple in the stream. THe water keeps flowing past the ripple, and the ripple never stops. That is the flux where Robin lives, and she is the only being to live there. She has mastered the ways of black magic and wishes to come out of the ripple and into the stream so she can rule the multiverse. To do this, she keeps building on her connection to our reality with a ‘game’ that made it out of the ripple. Every time you use it, you lose part of your essence and it flows into her. To stop people from finding out, she filled out all the multiples of 9 in the gift chart with the same gift, and hence people would stop at that conclusion. Those. People. Are. Wrong. STOP PLAYING THE GAME BEFORE SHE BREAKS LOOSE!!!

The Logical Explanation: She just uses Multiples of Nine on the chart with the same gift. For example, let’s say 9 is a “Wrist Watch.” Then poof, 18, 27, 36, 45, 54 etc. become “Wrist Watch” as well. When you hit start over, then 9 changes, so it could become “Undead Army to Rule the World” Then, 18, 27, 36, 45, 54 etc. would become “Undead Army to Rule the World”

156. Morpheous Says:

@ ZOMBEH

I love you

157. Nina Says:

what????? OH i get it, but im still gonna have nightmares!

158. zak Says:

what is the mind trick?

159. iThink Says:

okkkkkkk zak. If you haven’t read the rest of the discussion by now, try this explanation.
Any two digit number which you subtract like they tell you WILL be a multiple of nine. All the multiples of nine on the board are the same. Every time you play, they change the board, so all the multiples of nine are the same, try it and you’ll see, so for example the first time you play, all the multiples of nine are an oven mitt, the second time you play, all the multiples of nine are a bread board or whatever…the mind trick is that the average joe doesn’t realise that they change the gifts on the board every time, so you are baffled when she guesses it right.

160. hilary Says:

but you don’t put your number anywhere so i still dont get how it guesses your number everytime :S :L im shocking at maths so this is all gobledegoop to mee haha

161. 淘宝刷钻软件 Says:

be a multiple of nine. All the multiples of nine on the board are the same.

162. Andrea Says:

Read Ken’s response, that explained it.

If every number is a multiple of 9 and there are only 10 answers available, those 10 boxes will be the same every time.

What changes is what is in that box. Every time you replay the “36” “45”, and “63” etc will all be the same gift. It will change every time, and guess that same gift.

Still don’t get it… watch one number “36” every time will be a different response, which is the answer.

163. Michael Dyer Says:

the way i found out how to get it was, i started w/ the lowest number possible, 10,and got 9 as my outcome. then i tried it with 11. same result. this will go one consecutively until you reach 20, where you get 18. and, just like the last, every number in the 20s has an outcome of 18.
this continues with the 30s being 27, the 40s being 36, and so on.
so the only answers you can get are multiples of 9. when i looked at these numbers, i realized that all the gifts assigned to those numbers were the same! the way it tricks you into believing that you are getting different results, is that the gifts change every time, therefore creating the illusion that you are getting different gifts as your answer, and not tempting you to look at your numbers.

164. Fruldy Fromentin Says:

look the forum at curiousmatth.I had the same idea.
Post subject: The Pattern of the Multiplication Table 9( my best topic ) Posted: Jul 09, 2005 – 02:51 PM

Joined: Dec 14, 2003
Posts: 55

This Pattern of the Multiplication Table 9 is a mathemical observation of number greater than 9. All number greater than 9 are able to produce a number that are in the multiplication table 9.
1. Take any number greater than 9
2. add all digits that make the number
3. subtract the sum of digit from the number
Example1
let find the pattern of the multiplication table 9 of those following numbers: 10,11, 12,13,14,15,16,17,18,19
10
1)let add the digit that make 10: 1+0=1
2)let subtract result 1 from the number: 10-1=9
11
1)let add the digit that make 11: 1+1=2
2)let subtract result 1 from the number: 11-2=9
12
1)let add the digit that make 12: 1+2=3
3)let subtract result 1 from the number: 12-3=9
13
1)let add the digit that make 13: 1+3=4
2)let subtract result 1 from the number: 13-4=9
14
1)let add the digit that make 14: 1+4=5
2)let subtract result 1 from the number: 14-5=9
15
1)let add the digit that make 15: 1+5=6
2)et subtract result 1 from the number: 15-6=9
16
1)let add the digit that make 16: 1+6=7
2let subtract result 1 from the number: 16-7=9
17
1)let add the digit that make 17: 1+7=8
2)let subtract result 1 from the number: 17-8=9
18
1)let add the digit that make 18: 1+8=9
2)let subtract result 1 from the number: 18-9=9
19
1)let add the digit that make 19: 1+9=10
2)let subtract result 1 from the number: 19-10=9

* 20 to 29 will give the result of 18
* 30 to 39 will give the result of 27
* 40 to 49 will give the result of 36
* 50 to 59 will give the result of 45
* 60 to 69 will give the result of 54
* 70 to 79 will give the result of 63
* 80 to 89 will give the result of 72
*90 to 99 will give the result of 81

For every parameter of number, the number is repeated 10 times. Every number in the multiplication table 9 creates a loop for every number parameter greater than 9.

Last edited by Fruldy on Nov 06, 2005 – 05:29 PM; edited 1 time in total