Teaching Elapsed Time

Submitted by:Nicole Dawson, Nipissing University 2004 - 2005

During my placement in a grade 4 class I had a very difficult time getting the students to understand elapsed time and how to calculate it. I tried as many different methods as I could think of, however, none seemed to work. Finally, after some long and hard contemplation and reflection on how awful my lesson was, I came up with a method that most of the class could understand (including the level 1 students) and which they even used on their unit test. I call it the chart method. Actually, I told the kids it was Mrs. Dawson’s Method!

As an example, assume that you need to determine the elapsed time between 1:43 and 4:16.Using the chart below, the first step would be to calculate how many minutes you need to add to 1:43 to make it a “Friendly Time” (like “Friendly Numbers”).

Hours / 5 min / 1 min
//

So, the closest Friendly Time to 1: 43would be 1:45. Insert two tally marks in the 1 minute column.

Hours / 5 min / 1 min
// / //

Next, you would calculate how many full hours you

need to move the minute hand without going past

the end time of 4:16. Thus you proceed:

1:45 – 2:45is one hour; put one tally mark in the hour column. Next,

2:45 – 3:45is another hour; put one more tally in the hour column.

3:45 – 4:45, you have gone past 4:16; thus, you arefinished with hour box.

Hours / 5 min / 1 min
// / ////// / //

Now, you calculate the 5 minute intervals

between 3:45 and 4:16. You proceed as follows:

3:45 – 3:50is one five minute interval; put one tally mark inthe 5 minute column.

3:50 – 3:55is another five minute interval; put one

more tally mark inthe 5 minute column.

3:55 – 4:00 isanother five minute interval; put a tally mark

inthe 5 minute column.

4:00 – 4:05is another five minute interval; put tally mark

inthe 5 minute column.

4:05 – 4:10is one five minute interval, put one tally mark in the 5 minute column.

4:10 – 4:15 is one five minute interval; put one more tally in the 5 minute column

Finally, 4:15 – 4:20;you have gone past 4:16, thus you are finished with 5 minute box.

Hours / 5 min / 1 min
// / ////// / ///

Now you need to calculate the time from 4:15 – 4:16.

This is one minute, so you need to put one tally mark in

the 1 minute column.

Now add up all the tally marks in each column to calculate your elapsed time:

2 hours and 33 minutes – this is the elapsed time!!!!!!