Question

students arrived at the science museum at 1:15pm they stayed at the museum for 2 hours 51 minutes.What time did the students leave the museum?

Answer 1

1.15 plus 2 hours is 3.15 3.15 plus 51 is 4.06

Answer 2

The best way to solve problems like this is to add the hours, then the minutes.  Adding 2 hours to 1:15 is 3:15.  Adding 51 minutes to that would be 3:66, but 66 is over sixty, so it's an invalid amount of minutes.  Therefore, you'd subtract 60 of those minutes and add 1 more hour, for a result of 4:06 PM.  :)