--- title: "Comparing Time Durations" description: "Compare durations of events and calculate the time taken by particular events or tasks" canonical: https://lightmysky.com/learn/mathematics/comparing-time-durations-mt_4emC463IyW source: https://lightmysky.com/learn/mathematics/comparing-time-durations-mt_4emC463IyW.md retrieved: 2026-10-19 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Comparing Time Durations Compare durations of events and calculate the time taken by particular events or tasks Subject: Mathematics · Area: Measurement · Ages 7 to 8 Page: https://lightmysky.com/learn/mathematics/comparing-time-durations-mt_4emC463IyW ## Ready when they can - Calculate how long an activity lasted given start and end times - Compare the duration of two events and identify which was longer - Solve a problem such as 'The lesson starts at 10:15 and ends at 11:00. How long is it?' ## Lesson: How Long Did It Take? Duration means how much time something takes. To find a duration, look at the start time and the end time. Then count what happened in between. You already know how to read a clock and use minutes and hours, so this just puts that to work. *(drawing: This clock shows 10:15. A lesson starts at this time.)* **Example.** The lesson ends at 11:00. Count on from 10:15: first to 10:45 is 30 minutes, then to 11:00 is 15 more minutes. Add them together: 30 plus 15 is 45 minutes. The lesson lasted 45 minutes. *(drawing: Recess lasts 15 minutes. A movie lasts 90 minutes. The taller bar shows the longer event, so the movie takes more time.)* **Tip.** When you compare two events, the one with more minutes is the longer one. If the time crosses into a new hour, count up to the new hour first, then add what is left. Remember that 1 hour equals 60 minutes, so 60 minutes always beats a smaller number. **Recap.** To find a duration, count from the start time to the end time. To compare durations, more minutes means longer. ## Practice 17 questions on this page, each with its working shown. ## Needs first - [Estimating and reading time](https://lightmysky.com/learn/mathematics/estimating-and-reading-time-mt_3XJkeIn6J6) - [Time Units and Calendar Facts](https://lightmysky.com/learn/mathematics/time-units-and-calendar-facts-mt_EXlmTURK_o) ## Opens up - [Elapsed time problems](https://lightmysky.com/learn/mathematics/elapsed-time-problems-mt_IL86kadLSS)