Board Thread:Local Games/@comment-25344936-20150904010330/@comment-25104452-20150908201741

How to prove that 9 + 10 = 21 is true:

1. Factor out 9 and 10. You will get 3*3 and 5*2.

2. Now, do 3*2 and 5*3 and you will get 6 and 15.

3. Add 6 and 15 together and you will get 21.