It takes Matt 2 minutes per problem to do his math homework with a calculator and 5 minutes per problem without a calculator. If Matt's assignment has 20 problems, how much time will using a calculator save?
First find the time difference per problem: 5 minutes/problem - 2 minutes/problem = <<5-2=3>>3 minutes/problem
Then multiply that number by the number of problems to find the total time difference: 3 minutes/problem * 20 problems = <<3*20=60>>60 minutes
#### 60