Consider the question. Jessa needs to make cupcakes for 3 fourth-grade classes that each have 30 students and a P.E. class with 50 students. How many cupcakes does she need to make?
 If the answer is '140'; explain the reasoning:
For the fourth - grade classes, Jessa needs 3 classes * 30 cupcakes / class = 90 cupcakes. Adding the cupcakes for the P.E. class 50, she needs to make a total of 90 cupcakes + 50 cupcakes = 140 cupcakes.