Time differences | Math | 3rd grade | Khan Academy

TL;DR

Learn how to calculate the time difference between two clocks by breaking it down into hours and minutes.

Transcript

• [Voiceover] How much time has passed from the time on the left to the time on the right? So, we have a clock on the left and a clock on the right with different times shown, and we want to know how much time since the clock said, that read this first time, 'til it read the second time. We're also told the time passed is less than 12 hours. That's... Read More

Key Insights

• ⌛ The time difference between two clocks can be calculated by breaking it down into hours and minutes.
• ⌛ By determining the positions of the hour and minute hands, the time on each clock can be accurately determined.
• 🤗 Counting the minutes elapsed on the minute hand allows for precision in time calculations.

Questions & Answers

Q: How do you determine the time on a clock with an hour hand between six and seven and the minute hand at 43 minutes past the hour?

To determine the time on a clock with an hour hand between six and seven, and the minute hand at 43 minutes, start by recognizing the hour hand is closer to seven. Then, count the minutes elapsed on the minute hand from the top, resulting in 43 minutes past six.

Q: What is the time on a clock with the hour hand just past nine and the minute hand at 11 minutes past the hour?

The time on a clock with the hour hand just past nine and the minute hand at 11 minutes past the hour is 9:11. By observing the hour hand's position and counting 11 minutes on the minute hand, the time can be determined.

Q: How do you calculate the time difference between 6:43 and 9:11?

To calculate the time difference between 6:43 and 9:11, break it down into smaller parts. From 6:43 to 7:00 is 17 minutes. Then, from 7:00 to 9:00 is 2 hours. Finally, from 9:00 to 9:11 is an additional 11 minutes. Adding these together, the total time difference is 2 hours and 28 minutes.

Q: Why is it important to determine the positions of the hour and minute hands on the clocks?

Determining the positions of the hour and minute hands on the clocks is important because it allows us to accurately calculate the time difference. By knowing which hours the hands are pointing to and counting the minutes elapsed, we can determine the exact time on each clock.

Summary & Key Takeaways

• The video explains how to find the time difference between two clocks, considering the hours and minutes shown on each.

• The clocks shown have a time difference of less than 12 hours.

• By finding the hours and minutes separately, and adding them up, the time difference between the clocks can be calculated.