If magic doesn't exist...

[Curmudgeoness]

how does this work:

http://www.regiftable.com/regiftingrobinpopup.html

Drove me nuts, because you know all about "inquiring minds". I just knew there was a gimmick, and I have figured it out. See if you can.

[Avalux]

1. Hmm....

She guessed right when I subconsciously used my mouse to find my number. When I didn't do that, she guessed wrong. Was that your conclusion?

[Curmudgeoness]

4. Actually, she cannot guess wrong, unless you did the math wrong

on your number.

[mzteris]

2. it's a numbers/math equation

no "magic" involved. Just MATH.

[Curmudgeoness]

3. That doesn't explain how it works. Can you give details?

There is an explanation.

[rbnyc]

5. I figured it out. Don't read if you don't want to know.

Any 2 digit number when you subtract the composing digits will equal a number with digits that add up to 9. All the answers with digits that add up to 9 are the same regift.

[Curmudgeoness]

6. I think you mean.....

multiples of nine, right? 9, 18, 27, etc.

Good job. It took me a while to figure out that gifts were listed in more than one box. After that, it was a piece of cake.

[Ptah]

7. Multiples of nine add up to nine.

[Curmudgeoness]

8. Nine is not the only possible answer. If my number is 56,

then 56 less 5 is 51 and less 6 is 45. And 45 is not 9. But it will guess the right answer if you choose 45.

[rbnyc]

10. 4 plus 5 is 9.

XY - X - Y = ZQ. Z + Q = 9.

[Ptah]

11. The digits of 45 - - - > 4 + 5 = 9

[Curmudgeoness]

15. Nope, re-read the instructions. nt

[rbnyc]

23. Ptah and I are correct.

The instruction say pick a 2-digit numner, XY.

The instructions say, make this calculation: XY - X - Y.

You get AB.

The instructions say, look up AB.

Regifting Robin knows A + B will always = 9, so all answers in which the 2 digits that compose the number = 9 when added together have the same regift which is the one regifting robin will predict.

[Curmudgeoness]

26. No, it is not always 9. If you look at the instructions, the example

is 18. See if 18 works. It will.

[rbnyc]

28. 1 plus 8 = 9.

They want you to calculate XY - X - Y = AB. AB is your number. A + B will always = 9. They don't ask you to calculate that, but they know that, so on the chart every number in which the two digits that of the number are 9 when added together corresponds to the same gift, the one that will be predicted.

[rbnyc]

12. Hi

We're on the same wavelength.

:toast:

But you say it more clearly.

[Ptah]

14. My grandfather pointed that out to me when I was six or seven.

:thumbsup:

[rbnyc]

9. It's actually the same thing.

I didn't really grasp it was multiples of 9, but of course. Still, all 2-digit multiples of 9 are composed of digits that add up to 9. If you add up the digits of any multiple of 9, and then add the digits of the sum again and again until you get a one-digit number, it will always be 9.

[Curmudgeoness]

13. Re-read the instructions. The only choice is not 9.

Subtract the first and last numbers of your two digit number. The number 98 less 9 is 89 and less 8 is 90. See if it guesses the right number when you look for 81.

Oops, editted to correct my math. Gads.

[Ptah]

16. "The number 98 less 9 is 89 and less 8 is 90. "

98 - 9 = 89

89 - 8 = 81

8 + 1 = 9

[Curmudgeoness]

18. Oops, you are right at the 81 being the solution to my 98 example

but you are taking this a step too far. The regifting robin does not ask you to add the two digits together.

You just take your number, subtract the first digit from it, then subtract the second digit from it. You took it a step too far.

[rbnyc]

20. It doesn't ask you to...

...but it knows the outcome if you did which is why it can make the prediction.

[Curmudgeoness]

21. What is the outcome of their example? It is 18, not 9.

And if you find 18, it will guess your gift too.

[rbnyc]

25. 1 = 8 = 9

[Curmudgeoness]

27. But they did not tell you to take that step. Look and see if 18 works.

It will also work. Nine is not the only correct answer that will work.

[Ptah]

29. One last try

Any two digit number treated like that will result in a number divisible by nine.


All of the numbers that are factors of nine will have the correct gift.

I spot them by adding the digits.

[Curmudgeoness]

31. This is correct. I will try to explain it simply here.

If you look at 9, 18, 27, 36, 45, 54, 63, 72, and 81, they all list the same gift. So since those are the only possible answers, it will always guess the right gift, but you don't really notice right away that all those numbers have the same gift listed.

[rbnyc]

32. Right!

:toast:

[Ptah]

33. But I do notice.

[Curmudgeoness]

35. Wish I would have noticed quicker. It would have saved my brain

from working too hard when I was figuring this out.

[rbnyc]

30. Of course they don't tell you to take that step...

...that's the trick. They know 1 + 8 is 9, so 18 has the right gift, as does 27, 36, 45, etc. When you start with a 2-digit number, XY, XY - X - Y will always be 18, 27, 36, 45, etc. i.e. number where if you add the 2 digits, you get 9.

I'll keep finding ways to phrase this until you realize I'm saying the same thing you already realize, you just can't tell I'm saying it.

;-)

Edit: typo

[Curmudgeoness]

34. I agree that you are saying the right thing now. I tried to explain

in #31 in a simple way. Sorry if I wasn't getting what you were saying. I was bothered with everyone being stuck on "9".

I am always the one that gets sent these stupid things to try to figure out for all my friends. Because I just can't give up finding a gimmick.

[rbnyc]

36. My brain is wierd.

It's more natural to think of multiples than to think how the digits within a numner add up, I mean that's numerology, right? Not math. I took you on a Rene-brain detour, but I knew we were trying to say the same thing.

Edit: I can no longer type. I've also had 2 hours of sleep in the last 48.

[Curmudgeoness]

38. OMG, and you were dealing with this problem on no sleep!

You are much smarter than I can hope to be! Go to bed!

[rbnyc]

39. I don't know why I'm up.

I had an event last night at work and a meeting early in the morning. I have tons to do tomorrow. I'm just in this posting loop. I actually am not totally convinnced that I'm awake.

;-)

[Curmudgeoness]

40. Addiction to DU. Gotta love it.

Wonder if there is a hotline for this.

[struggle4progress]

45. It's a well-known divisibility test: a number is divisible by 3 (or by 9) exactly when

the sum of its digits is divisible by 3 (or by 9)

There's a similar quick way to compute the remainder when dividing by 3 (or by 9); just sum the digits repeatedly until you get a one digit number, then compute the remainder: for example, to find the remainder of 1237 when divided by 3 or by 9, sum the digits 1 + 2 + 3 + 7 = 13; repeat until you get a one digit number 1 + 3 = 4; now divide; 4 leaves a remainder of 1 when divided by 3, and 4 leaves a remainder of 4 when divided by 9; so 1237 leaves a remainder of 1 when divided by 3, and 1237 leaves a remainder of 4 when divided by 9

[Ptah]

22. "Step too far"? Any two digit number treated like that will result in a number divisible by nine

All of the numbers that are factors of nine will have the correct gift.

I spot them by adding the digits.

[rbnyc]

17. Wiat, my head exploded

I defer to Ptah

[Curmudgeoness]

19. Ptah doesn't have it yet either. But you are both tiptoeing around it.

Both so close.

[rbnyc]

24. No we're not...

You're just not hearing us.

We know it doesn't ask us to add up the digits of the number we come up with. What we're saying is that it knows that if we did, the answer would always be 9, therefor all answers in which the sum of the composing digits are 0 have the regift that will be predicted.

[Curmudgeoness]

37. Thanks for the discussion, and having me confused too. Explanation

is in #31 for anyone who still wants to know.

[janet118]

41. Numbers are magic, especially number 9, number 9 . . .

Number 9 Magic Card Trick

[Curmudgeoness]

42. Neat trick. If only I can remember all the steps right!

Knowing me, I would forget a step.

And yes, 9 is magic. Us accountants are always looking for multiples of 9.

[Duer 157099]

43. I did it 3 times in a row, with different numbers, different gifts

and all 3 were correct. I didn't use the mouse to give any clues.

I'm confused!!!!!!

edit: doh! OK now I get it. Each time, it changes which gifts it associates with each number. Doh!

[burrfoot]

44. Thank you!

That's the part that was missing, and making me feel dumb. I hadn't realized that it changes the gift each time. :)

[EnviroBat]

46. Gaaaah! All of the multiples of 9 are the same gift!

So it doesn't matter what your number ends up being 9,18,27,36... Could be an multiple of nine that you arrive at from the algorythm xy - x - y = n. n will always be a factor of 9. If you look at the chart, all of the multiple of nine are the same gift.

The real "gift" is the newly acquired computer virus that we all have now. Thanks bunches!!!

[chrisa]

47. Haha that's easy. It uses multiples of 9.

For example, 14, 14-1-4 = 9. 9 Says "Cuff links," as do all of the digits of 9. 18; 18-1-8 = 9; 99 99-9-9 = 81, a multiple of 9. 76-7-6=63, another multiple of 9.


Try it for any number. It will always be a multiple of 9. All of the multiples of 9 have the same answer. Therefore, the computer is always right. :)