Free interactive math game: Time Elapsed — Watch. Part of the Units & Time category on MathKite.
Taken from the generator that powers this exercise. A fresh set appears every time the page is opened, and the printable worksheet holds ten of them.
Working out how much time has passed between two moments.
Count up to the next whole hour first, then add the remaining whole hours, then the leftover minutes.
From 14:40 to 17:15 there are 20 minutes to 15:00, then 2 hours to 17:00, then 15 minutes — 2 hours 35 minutes.
Subtracting the times as ordinary numbers. 17.15 minus 14.40 gives nonsense, because minutes stop at 60.