Time, am and pm, and How Long
Solve problems involving the duration of time including situations involving am and pm and conversions between units of time.
Read this first
Count on from the start time. Do the hours first, then the minutes.
From 9:40 to 10:40 is one hour. Then 35 more minutes.
Words you need
- am
- Before midday.
- pm
- After midday.
- Duration
- How long something takes.
Worked example
e.g. A film starts at 9:40 am and ends at 11:15 am. How long is it?
- Jump whole hours first. 9:40 to 10:40 is 1 hour.
- Jump again. 10:40 to 11:15 is not a whole hour. Stop.
- Count the minutes from 10:40 to 11:15. That is 35 minutes.
- So the film is 1 hour and 35 minutes.
Hours first, then minutes. Never try to do both at once.
Practice
The pictures fade as you go. By the last few you are on your own.
1How long from 2:00 pm to 4:30 pm?with a picture
Answer2 hours 30 minutes.
2How long from 7:15 am to 8:00 am?with a picture
Answer45 minutes.
3How long from 11:30 am to 1:00 pm?with a hint
Need a hint?
Go to 12:00 first.
Answer1 hour 30 minutes.
4How many minutes in 3 hours?with a hint
Need a hint?
One hour is 60 minutes.
Answer180 minutes.
5Is 7 o'clock in the morning am or pm?on your own
Answeram.
6A bus takes 50 minutes. It leaves at 3:20 pm. When does it arrive?on your own
Answer4:10 pm.
7How many hours in 2 days?on your own
Answer48 hours.
Think about it
1
Why go to 12:00 first when crossing midday?
One good answerIt breaks a hard jump into two easy ones.
2
What time is 12 noon, am or pm?
One good answerNeither. We call it noon or midday.
Common mistakes
Treating time like normal numbers.
There are 60 minutes in an hour, not 100.
Forgetting am and pm.
8:00 am and 8:00 pm are twelve hours apart.