There has got to be a mathmatical explanation for this. Please explain it to me. I am stupid.?

Question

http://www.mysticalball.com

I got you. That makes perfect sense. I told you I am stupid.

Answer 1

Let the digits of your number be A and B.

Your number is 10A + B
Subtracting the digits you get:
10A + B - (A + B)
= 9A

In other words, you'll always end up with a multiple of 9.

If you look at the symbols next to all the powers of 9 (9, 18, 27, 36, etc.) it is the secret symbol. (They stop at 81, because your top digit A can't be higher than 9).

All the rest of the symbols are chosen randomly so it makes it hard to see that the multiples of 9 are the same.

No magic, just math.

Answer 2

This works because subtracting the sum of the digits of any number from itself yields a number divisible by 9. So, if you look at the symbols next to 9, 18, 27, etc., you will see that they are all the same. Except for 90 and 99, but those are impossible to reach starting with a two digit number.

The proof of divisibility by 9 is fairly easy. First consider all powers of 10. They all have a 1 followed by some number of zeros. The sum of their digits is 1. subtracting 1 from them gives a number consisting of nothing but 9's.

10 - 1 = 9
100 -1 = 99
1000 - 1 = 999

Now consider a number that is a single digit followed by zeros, like 3000. Subtracting 3 gives 3000 - 3 = 3*(1000 - 1), so it clearly works with these numbers.

Finally, you can write any integer as a sum of numbers, each term of which is a single digit followed by zeros.

example: 3548 = 3000 + 500 + 40 + 8

Subtracting the sum of the digits gives, after rearranging, (3000 - 3) + (500 - 5) + (40 - 4) + (8 - 8)
and each of these terms is divisible by 9

Answer 3

There is a mathematical explanation.

If you choose any 2-digit number from 10-19, add the two digits and subtract that from your original number, you get 9.

From 20-29, you get 18.

From 30-39, you get 27.

Notice a pattern? All of the possiblilities are multiples of 9, which all have the same symbol.

9 is really cool like that ;o)

Answer 4

Let 10a+b be a two digit number with digits a and b. Then the number you obtain by subtracting the total of the digits from it is 10a+b - (a+b) = 9a. So now, you notice how all the multiples of 9 from 0 to 81 all have the same symbol? That's how it gets your number -- because the result of your calculation MUST be a multiple of 9, and since a is a single digit, the result MUST be less than or equal to 81.

Answer 5

Try 10 at random without clicking the crystal ball. Look at the answers - you'll see they all have the same symbol next to them. This is because all possible answers have the same symbol. This is because every possible answer has to be a multiple of 9. Look at the great algebraic formuals above.
And you're not stupid - you didn't belive it was actually reading your mind, but figured there must be a logical explanation. Way to go!

Answer 6

LET X = FIRST DIGIT AND Y= SECOND DIGIT IN NUMBER YOU CHOOSE
10x+y-(x+y)= 9x
If you look at the chart, you will notice that every multiple of 9 has the same flower symbol.

Answer 7

All the multiple of 9 have the same symbols in any screen, which is the answer always. other symbols are there to distract U.