Wanna have more fun with numbers ?
Try these.

1)Write down your age
2) Multiply it by 3.
3) Add 1 to the total
4) Multiply that by 3
5) Add the original number (your age)

Then you ask for the total. Suppose that someone writes down 23. They multiply it by 3 getting 69. The person adds 1 getting 70. It is multiplied by 3 equaling 210 and the original number is added which equals 233. When you are told this number you take away the last digit. This gives you 23, which is the original number.

You will need 3 dice. Give the person 3 dice saying, ??When my back is turned please roll these 3 dice.? Now tell the person these directions:
1) Multiply the number on die one by 2.
2) Add 5
3) Multiply by 5
4) Add the number from die 2 to the total
5) Multiply by 10
6) Add the number on die 3 to the total

Finally say, ??What total did you get?? You subtract 250 from the number. Suppose the person tells you 612. 612-250=362. So the numbers showing on the dice are 3, 6, and 2.