Number trick that always equals 5

by Dudley
(Roseville, CA. U.S.A.)

1. Think of any positive whole number. No fractions, no decimals, and no percents.

2. Double that number.

3. Add 10 to that result in step 2.

4. Divide the result in step 3 by 2.

5. Subtract the number in step #1 from the number in step #4.

6. The answer will always be 5.


Let x be the number

Double x : 2x

Add 10 to 2x : 2x + 10

Divide the number by 2: (2x + 10) / 2 = x + 5

Subtract x from x + 5: x + 5 - x = 5

The answer is 5


Example


Let 8 be the number

Double 8: 16

Add 10 to 16: 26

Divide 26 by 2: 26/2 = 13

Subtract 8 from 13: 13 - 8 = 5