You completed 9 problems of your math homework. You have 6 problems left. How many problems were you assigned for homework? Which answer shows how to solve the problem?
Subtract: 9 – 6 because you have 6 problems left.
Subtract: 9 – 6 because you are given the total and a part and need to find the other part.
Add 9 and 6 because both numbers are less than 10.
Add 9 and 6 because you are given two parts and asked for the total.