Elapsed Time (990)

Teaching Notes

This collection focuses on elapsed time. Ensure students understand the relationship between seconds, minutes, hours, and days.

Vocabulary

Elapsed Time: The amount of time that has passed.

Start Time: The time when an event begins.

End Time: The time when an event finishes.

Common Mistakes

• Confusing the conversion factors (60 vs 24)
• Multiplying instead of dividing
• Forgetting to label units
• Miscalculating elapsed time across AM/PM boundaries
• Subtracting minutes like base 10.
• Forgetting to borrow from hours.
• Miscalculating across midnight.
• Confusing AM/PM.

Differentiation

Discussion Questions

• Why are there 60 minutes in an hour?
• How do you calculate time difference?
• When would you use seconds instead of minutes?
• How does a number line help visualize time?
• When is calculating elapsed time useful in daily life?
• What strategy do you use when the end time is on the next day?
• How can you check if your elapsed time answer is correct?

Extension Activities

• Create a daily schedule.
• Time activities in the classroom.
• Calculate the duration of a movie or event.

Parent Tip

Ask your child to calculate the time until dinner.

Skill Cluster

Measurement and Data

Estimated Time

15 minutes

Skills Practiced

Prerequisites

• 989
• Telling Time to the Minute
• Basic Subtraction

Next Steps

• Time Conversions
• Word Problems with Time
• Scheduling Events
• Telling Time to the Nearest Minute
• Problem Solving with Time