Problem
First name
Conor and Alex
School
Gospel Oak Primary School
Country
Age
11
It works because you are pretty much doing the same sum each time but just getting 1 higher than the sum before with means that you’ll always end up with a number in the 9 times tables with is the right answer. For example :
10 1 + 0 = 1 10 - 1 = 9
11 1 + 1 = 2 11 - 2 = 9