Actually, the answer SHOULD have been 83.5, since, according to the math rules of operation, you should do the division before you do the addition. So 63 divided by 2 is 31.5. 26 plus 89 is 115. 115-31.5 = 83.5.
When I saw the math problem on the black board, I figured they weren't going to do it correctly. Then I noticed that they had different math problems on different boards.