What's the answer to this?

4 + 10 / 2 = ?

Did you get 7?

Do you see how the answer could be 9?

There are two possible ways to do this problem:

4 + 10 / 2
 

Do the addition first:

4 + 10 / 2 = 14 / 2 = 7

Do the division first:

4 + 10 / 2 = 4+5 = 9