Thanks for entertaining my mind for a while....
I hope what I'm about to write does not kill the fun... and I also hope you won't hate my long post, or the math in it
1. Note that whenever you click on the area where the character you've just thought of is to appear, the next screen has the characters reset.
2. Nevertheless... do this experiment... take note of the character associated with number 0, click on the box... you get the same character that was associated with number 0 right? Now do it again... and again... and again... same happens!... hmmm something smells fishy
3. Now... what other numbers have the same character as number 0? It will always be 9, 18, 27, 36, 45, 54, 63, 72 and 81... what's with these numbers? they all are integer multiples of number 9.... hmmmm something smells really fishy
4. It is a fact that substracting the sum of the two digits of a number from the original number you get an integer multiple of 9, the proof: (back to basic algebra):
Let 'n' be an integer number
Let 'A' be an integer number to represent the tens in the number
Let 'B' be an integer number to represent the units in the number
thus you can write:
n = 10A+B
Let 'D' be the difference of the number 'n' and the sum of its two digits 'A+B'
Then:
D = n - (A + B) = (10A+B) - (A - B) = 10A + B - A - B = 9A
You see? D = 9A, since A is an integer... D must be an integer multiple of 9...
What a coincidence!!!
5. Summary. When you pick a number and find the difference of it and the sum of its digits, the result is a multiple of 9, all the characters in the set associated with multiples of 9 are the same, and it is the character to appear in the box when you click on it, there is no chance that you'll get another answer, and the rest of the numbers in the set are garbage :rofl:
You're safe!! no one is reading your mind! you can look at the screen of your computer with trust... (at least with respect to this issue)
Now, I need a drink :beer: :beer: