Question

Mark gets picked up by the bus at 7:40 he arrives at school at 8:10 how long does it take to get to school

Answer 1

You could do this in two ways, you could either subtract immediately or convert the time given in hours into minutes
STEP 1:
8:10
- 7:40
which will give 0:30
STEP 2:
8 hours 10 minutes into minutes is
(8 * 60) +10 = 490 minutes
7 hours 40 minutes into minutes is
(7*40) + 40 = 460 minutes
490 - 460
= 30minutes

Answer 2

It takes mark 30 minutes