Answer :

ollieboyne
He is adding 6 + 2 to get 8.

However, he should add -6 and 2, to get -4.

He can then use 9+-4 = 9-4 = 5.

Alternatively, he could do:

9 - 6 = 3

3 + 2 = 5
going from left to right 9-6=3 then 3+2=5 ... his mistake was that he solved the problem right to left.

Other Questions