Elapsed time and telling time help students read clocks, follow schedules, and solve real-life time problems. This cheat sheet covers analog clocks, digital time, hour and minute units, and how to find time before or after an event. Students in grades 2 through 5 need these skills for school routines, word problems, and everyday planning.
The most important ideas are that hour equals minutes and that a clock face is divided into hour numbers. Each number on an analog clock represents minutes, so skip counting by helps read the minute hand. To find elapsed time, count forward from the start time to the end time using hours and minutes, or subtract when the times are easy to compare.
Key Facts
- hour equals minutes.
- minute equals seconds.
- On an analog clock, the short hand shows the hour and the long hand shows the minutes.
- Each number on a clock face stands for minutes, so the minute hand on means minutes.
- To find elapsed time, use when both times are in the same part of the day.
- To find an end time, use .
- To find a start time, use .
- When adding minutes, trade minutes for hour if the minutes reach or more.
Vocabulary
- Analog clock
- A clock with hands that point to numbers to show the hour and minutes.
- Digital clock
- A clock that shows time with numbers, such as .
- Elapsed time
- The amount of time that passes between a start time and an end time.
- Minute hand
- The longer hand on an analog clock that shows the number of minutes after the hour.
- Hour hand
- The shorter hand on an analog clock that shows the hour or the hour the time is moving toward.
- Interval
- A length of time between two times, such as minutes or hours.
Common Mistakes to Avoid
- Reading the hour hand as the minute hand is wrong because the short hand gives the hour and the long hand gives the minutes.
- Counting each clock number as minute is wrong because each number represents minutes for the minute hand.
- Forgetting to regroup minutes as hour is wrong because times like are not valid clock times.
- Subtracting the larger minute number from the smaller minute number without regrouping is wrong because minutes must be borrowed from an hour when needed.
- Ignoring a.m. and p.m. can give the wrong elapsed time because a.m. to p.m. is hours, not hours.
Practice Questions
- 1 What time is minutes after ?
- 2 How much time passes from to ?
- 3 A movie starts at and lasts hour minutes. What time does it end?
- 4 Why is counting by useful when reading the minute hand on an analog clock?