Understanding Mixed Time Units
Time is all around us!
When we work with time, we often need to add or subtract different units like hours, minutes, and seconds.
Just like with money (dollars and cents), we need to be careful when converting between these units.
Remember: 1 hour = 60 minutes, and 1 minute = 60 seconds.
How to Add and Subtract Time
1️⃣ Write the times vertically with hours, minutes, and seconds lined up
2️⃣ Add or subtract each column separately
3️⃣ Convert when needed - if seconds or minutes reach 60, convert to the next higher unit
Let's Practice Together!
Example 1: Adding Time
Sarah practiced piano for 1 hour 25 minutes and violin for 45 minutes. How much total time did she spend practicing?
Try it yourself: h min + h min =
Solution: 1 hour 25 minutes + 45 minutes = 1 hour 70 minutes = 2 hours 10 minutes
Example 2: Subtracting Time
A movie is 2 hours 15 minutes long. If you've watched 1 hour 40 minutes, how much time remains?
Try it yourself: h min - h min =
Solution: 2 hours 15 minutes - 1 hour 40 minutes = 1 hour 75 minutes - 1 hour 40 minutes = 35 minutes
Parent Tips 🌟
- Use real-life examples: Calculate total screen time, practice durations, or cooking times to make it practical.
- Visual aids help: Draw clock faces or use a physical clock to show how minutes become hours.
- Make it a game: Time household activities and have your child calculate totals or differences for rewards.