Question: I need help with this problem:
There are 96 fourth-graders at Small Tree  School. 43 of them are girls. On Friday, 5 fourth-grade girls and 4 fourth-grade boys were absent. How many fourth grade boys were at Small Tree  School on Friday?
Answer: 
Of the 96 fourth graders, 43 are girls, so 96 students - 43 girls = 53 boys.
On Friday there were 53 boys - 4 absent = 49 boys.