**Teaching-elapsed-time-is-hard.**It’s one of those concepts that 3

^{rd}grade students find so difficult to understand and even more difficult to master.

Add to that – some students are still learning how to tell time which creates layers of skills that need to be addressed simultaneously.

But…it can be done if you use math models that make it visual for learners. There are two that I really like, and I like to teach both: Number lines and T-Charts.

If you model these two methods explicitly for students and then allow them to practice – they will get it – I promise.

**Teaching Elapsed Time Using Number Lines**

This is my

*favorite*math model for teaching elapsed time.Why? Students are already familiar with the concept of number lines. They have learned and used them for a few years, so the only new aspect is using hashmarks to notate time instead of numbers or fractions.

*Using established math learning helps them begin this new learning with confidence!*Here’s how to teach elapsed time to the hour and half hour using number lines:

**Elapsed Time Number Line Steps:**

*Given a start time of 2:00 and an end time of 4:30.*

Step 1: Draw a number line with a start time of 2:00.

Step 2: Count forward one hour and place a hashmark on the number line labeled

3:00. Draw an arc from 2:00 to 3:00 and label 1 hour.

Step 3: Count forward one hour, place a hashmark on the number line labeled

4:00. Draw an arc from 3:00 to 4:00 and label it 1 hour. Now count

forward 30 minutes and place a hashmark half as far as the hour marks

and label it 4:30. (half as far helps students see that 30 minutes is half of

1 hour) Now draw an arc and label it 30 minutes.

Step 4: Add all the labeled hours and minutes together to find the total elapsed

time.

**Teaching Elapsed Time Using T-Charts**

This math model is another way to calculate elapsed time. I like it to use it when there is a lot of time (5 or more hours) between the start and stop time. It’s easier to list all of the times in a chart versus a number line. But either way – students can choose their preferred method.

**Elapsed Time T-Chart Steps:**

*Given a start time of 2:00 and an end time of 4:30.*

*Step 1: Draw a chart in the shape of a T. Label “Time” on the left side and*

“Hours/Minutes” on the right. Write the start time first.

Step 2: Count forward one hour and write 3:00 below it. Draw a V from 2:00 to

3:00 and write 1 hour under the Hours/Minutes column.

Step 3: Do the same for 3:00 to 4:00 and 4:00 to 4:30 writing the elapsed time

on the right side.

Step 4: Add all the hours and minutes together to find the total elapsed time.

Once your students have learned these two math models for calculating elapsed time, they need practice.

**Meaningful Practice**

Use error analysis. It’s much more fun and challenging than just calculating start and stop times.

*See how I use error analysis in the classroom to challenge students – What I Wish Teachers Knew About Error Analysis.*Use real-world elapsed time word problems. This is a real-world skill, so give them real-world elapsed times to figure out.

### Go Digital!

These digital elapsed time error analysis task card activities are perfect for giving your students valuable practice with

**zero**prep for you! Available for Google™ Classroom right now in my store.This resource offers students two ways to respond to the questions: true/false multiple choice and short answer response.

In this set, all

*odd*numbered questions are multiple choice and all

*even*numbered are short response.

With 36 task cards – you have so many choices of how you will use this valuable resource! Use now for practice – later for mastery – then later for review – so many options!

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