Porche has 3 hours to get all her homework done. Her math homework takes her 45 minutes. Her English homework takes her 30 minutes. Her science homework takes her 50 minutes. Her history homework takes her 25 minutes. She also has a special project due the next day. How much time does she have left to get that project done? Think carefully first, then make a decision:
She has 180 minutes to do work because 3 times 60 equals 180. She has already spent 150 minutes on homework because 45 plus 30 plus 50 plus 25 equals 150. She has 30 minutes to finish her project because 180 minus 150 equals 30. So, the answer is 30.