Problem
First name
Aidan Stimpson
School
Coalbrookdale & Ironbridge C of E Primary School
Country
Age
11
I agree with Jonas because if you add 10 this doesn't work ,but with 9 it does. What's happening is, let's say you choose the number 10. 10+9= 19 and if you add the digits (1+9) you will get 10 (the number you began with).