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

# Answer

60
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
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?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
60
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?
train