Virginia SOL Math / Grade 4 / Measurement & Geometry

4.MG.2

Elapsed Time

What you'll learn

  • Solve elapsed-time problems within a 12-hour period
  • Find start time, end time, or elapsed time
  • Use analog and digital clocks to reason about time

Words to know

Elapsed time —
how much time has passed
Start time —
when an event begins
End time —
when an event finishes
a.m. / p.m. —
before noon / after noon
Interval —
a length of time, like 45 minutes

Why it matters Finding elapsed time keeps us on schedule, from knowing how long a trip takes to when an activity will end.

Worked examples

Model ItI do

A class starts at 9:15 and ends at 10:45. How long is it?

From 9:15 to 10:15 is 1 hour. From 10:15 to 10:45 is 30 more minutes. So the class is 1 hour and 30 minutes long.

Try It TogetherWe do

A movie is 2 hours long and ends at 5:30. When did it start?

Count back 2 hours from 5:30: 5:30 minus 2 hours is 3:30. So the movie started at 3:30.

Now YouYou do

Practice starts at 4:20 and lasts 1 hour and 15 minutes. When does it end?

Add the hours first, then the minutes, to the start time. Check your answer in the back.

Practice

Mastered 0 of 11

Warm-up

Ease in with the basics.

  1. 1.How many minutes are from 3:00 to 3:20?

  2. 2.How many minutes are in 1 hour?

  3. 3.A game starts at 1:00 and ends at 2:00. How long is it?

On Level

The core Quick Check from the book.

  1. 1.How many minutes are from 2:00 to 2:45?

  2. 2.A trip starts at 8:00 and ends at 11:30. How long is it?

  3. 3.An event lasts 3 hours and ends at 6:00. When did it start?

  4. 4.How long is it from 10:10 to 10:55?

  5. 5.Recess is 25 minutes and starts at 12:40. When does it end?

Challenge

Stretch your thinking.

  1. 1.A field trip starts at 9:45 a.m. and ends at 1:20 p.m. How long is it?

  2. 2.A movie lasts 1 hour and 50 minutes and ends at 4:15. When did it start?

  3. 3.Practice starts at 3:50 and lasts 1 hour and 40 minutes. When does it end?