time
Elapsed time for beginners
Find how much time has passed between two times.
Quick answer
Elapsed time is how much time passes between two moments. You can find it by counting forward or backward on a clock or number line.Learning outcome
By the end of this page, you will be able to find how much time has passed between two times using a clock, number line, or by counting hours and minutes. Success signs:- You can tell the time on an analog clock
- You can count forward or backward in hours and minutes
- You can use a number line to show time passing
- You can solve simple time problems in real life
Why this matters
Elapsed time helps you know how long things take. It's useful for planning your day, knowing when your favourite TV show starts, or understanding how long you've been playing a game. In school, you'll use elapsed time for science experiments, reading, and sports. In the real world, it helps you be on time for bus trips, cooking, and even when you're helping with a birthday party!How it works
To find elapsed time, you need to:- Look at the start time
- Look at the end time
- Count how much time passes between them
- Count forward on a clock
- Use a number line
- Count hours and minutes separately
Examples you can see
Let's look at some simple examples you can imagine or draw. Example 1: Counting forward on a clock If you start watching a movie at 2:15 and finish at 3:45, how long did the movie last? You can count forward on a clock:- From 2:15 to 2:30 is 15 minutes
- From 2:30 to 3:00 is 30 minutes
- From 3:00 to 3:45 is 45 minutes
- Start at 3:30
- Count forward to 4:15
- From 3:30 to 4:00 = 30 minutes
- From 4:00 to 4:15 = 15 minutes
- From 10:20 to 11:20 = 1 hour
- From 11:20 to 11:50 = 30 minutes
Try it as a mini adventure
Adventure: The Time Traveler's Journey You are a time traveler who needs to find out how long different adventures take. Your journey has three stops: Stop 1: The Zoo You arrive at the zoo at 9:15 and leave at 10:45. How long did you spend at the zoo? Stop 2: The Ice Cream Shop You start eating ice cream at 1:30 and finish at 2:15. How long did you enjoy your ice cream? Stop 3: The Park You start playing at 3:40 and finish at 4:55. How long did you play? Answer Key:- Stop 1: 1 hour 30 minutes
- Stop 2: 45 minutes
- Stop 3: 1 hour 15 minutes
Common mistakes
- Mistake: Thinking you can just subtract the hours and minutes separately without considering the minutes.
Why it happens: Children may forget that if the minutes of the end time are less than the minutes of the start time, they need to borrow an hour.
Fix: Always check if you need to borrow from the hour. If the end minutes are less than the start minutes, subtract 1 from the end hour and add 60 minutes to the end minutes. - Mistake: Counting only hours and forgetting minutes.
Why it happens: Children might focus only on whole hours and not notice the smaller time units.
Fix: Break the time into hours and minutes separately and add them together. - Mistake: Confusing start and end times.
Why it happens: Children might mix up which time is first and which is last.
Fix: Always double-check that the start time is before the end time.
Parent and carer guide
As a parent or carer, you can help your child understand elapsed time by:- Using a real clock or watch to show how time passes
- Playing time games during daily routines like cooking or travel
- Asking questions like "How long did your bath take?" or "How much time passed between when you woke up and when you ate breakfast?"
- Practicing with different start and end times
- Encouraging your child to draw number lines or use clocks to show their thinking
- "Let's count how long this game took"
- "Can you show me on the clock how much time passed?"
- "What time did you start your homework? What time did you finish?"
- Children may make small mistakes when counting
- It's okay if they need to use drawings or clocks to help them
- They don't need to memorize all the time facts right away
Practice questions
- If you start your maths homework at 3:20 and finish at 4:05, how long did you work?
- Tommy starts playing at 1:45 and finishes at 2:30. How long did he play?
- Lily starts her drawing at 10:10 and finishes at 11:25. How long did she draw?
- Emma starts her reading at 8:50 and finishes at 9:35. How long did she read?
- Ben starts his video game at 5:15 and finishes at 6:40. How long did he play?
- 45 minutes
- 45 minutes
- 1 hour 15 minutes
- 45 minutes
- 1 hour 25 minutes
FAQ
What is elapsed time?
Elapsed time is how much time passes between two moments. For example, if you start your lunch at 12:00 and finish at 12:30, 30 minutes have passed.
How do I find elapsed time?
You can find elapsed time by counting forward on a clock, using a number line, or by counting hours and minutes separately.
Can I use a number line for elapsed time?
Yes! A number line is a helpful tool. You can mark the start time and count forward to the end time to see how much time passes.
Why is elapsed time important?
Elapsed time helps you plan your day, know when things happen, and understand how long tasks take. It's useful for school, sports, and daily life.
What if the minutes of the end time are less than the minutes of the start time?
If this happens, you need to borrow an hour from the end time and add 60 minutes to the end minutes before subtracting. For example, if you start at 2:45 and end at 3:20, you can think of it as starting at 2:45 and ending at 4:20 (borrowing an hour), then counting: 2:45 to 3:00 = 15 minutes, 3:00 to 4:00 = 1 hour, 4:00 to 4:20 = 20 minutes. Total = 1 hour 35 minutes.