Elapsed Time

Elapsed time is the amount of time that passes. Third graders usually understand the concept of elapsed time, but it is often challenging for them to solve elapsed time problems. I found a new strategy that works amazingly well. I have copied the explanation here - it's not easy to explain. Monday afternoon your children will be bringing home some examples. They can show you better. Let me know if you have any questions. Have fun!

1. Jamie put a pizza in the oven at 1:25. It cooked for 30 minutes. What time was it when the pizza was ready to eat?

The student draws a t-chart. At the top on the left side write the start time-1:25. On the top at the other side write min. Next, make several horizontal lines going down the t-chart. Under "min." write 5, 10, 15, 20, 25, 30. On the other side, under 1:25, count up the time until it is on the same line as "30." The left side should say 1:30, 1:35, 1:40, 1:45, 1:50, 1:55. The answer is 1:55 and I have the kids circle it.

This will work with virtually any kind of elapsed time problem.

2. Kyle's soccer practice started at 4:10 and lasted until 4:40. How long did soccer practice last?
The student draws a t-chart. At the top on the left side write the start time-4:10. On the top at the other side write min. Next, make several horizontal lines going down the t-chart. Under the start time count up at five minute intervals until it shows 4:40. Under min. count up by fives until you are on the same line as 4:40 and there you have how much time has passed! (30 min.)

3. Tamia went to the mall at 2:20 and shopped for one hour and 10 minutes. What time was it when Tamia left the mall?

This time you will complete two t-charts, one for the hours and the other for minutes. Do the hour chart first. The student draws a t-chart. On top of the left side write 2:20. On the top of the right side write hours. Now make several horizontal lines and label the first underneath hours with 1. Now move 2:20 to 3:20. The next thing to do is create the minutes t-chart and use 3:20 as the start time.

Let me know how you do! :o)