Elapsed time is a hard concept for students to grasp, and in all honesty it can be one of the more challenging math skills to teach. Spending nine years teaching third grade gave me ample opportunity to experiment with different methods of teaching elapsed time. This post will explain what I found to be the best way to teach kids to calculate elapsed time.
There are several strategies students can use to solve elapsed time problems, but the one I find to be most efficient by far is the open number line. An open number line is effective and useful in so many areas of math.
I use it when teaching children how to add, subtract, round numbers, work with money and calculate measurements. It is a visual tool that helps them to truly understand the concepts. It is especially helpful when teaching your kids how to figure out the amount of time passed. It can be used to determine both the time that has elapsed between two given times, and also to use a specific time and a given number of hours and minutes that have gone by to figure out a starting or ending time for an event.
To use this strategy…
- Have the student draw an open number line.
- Record the starting time on the far left.
- Teach them to make jumps to “friendly, landmark” times.
- Record the time you land on under the number line and record the amount of time that has elapsed above the jump.
- Once you progress to the end time simply add up the increments of minutes above the jump, and if necessary, convert those minutes into hours and minutes.
Before students can calculate elapsed time they need to have some related mathematical concepts firmly in place.
Skills that Come Before Elapsed Time
- read time on analog and digital clocks
- write analog and digital time
- add and subtract fluently
- convert minutes to hours and hours to minutes
When Should Elapsed Time be Taught
Once students are proficient in the above skills, the concept of elapsed time can be introduced. It has proven to be one of the more challenging math concepts for kids to master so they will need repeated practice and exposure throughout the year.
I strongly advocate for using a spiral review approach to teaching all math skills. Children progress at different developmental rates and it is not effective to teach a “math unit” and then move on to the next ones without spiraling back throughout the year.
For this reasons, in combination with the fact that I felt WAY too much time was being wasted on test prep each spring, I created a yearlong series of spiral review print and go activity pages that have since proven to be effective in thousands of classrooms. I have used them for morning work (or bell ringers as some parts of the country refer to them), homework, as independent practice during math workshop while I do guided math with other students, as assessments, and I also include them in my substitute teacher plans.
So the long story answer to the question, “When should elapsed time be taught” is all year long. However, the short answer is ‘once the students have mastered the foundational skills needed to calculate elapsed time.’ The really short response is that I have always taught in in late October and early November in third grade.
Because of that timing, I created an Elapsed Time November Activity that applies the skill in a real-world situation. I made it to complement our unit study of The Pilgrims, the Wampanoag Native Americans, and the First Thanksgiving. This specific activity had students planning a field trip to Plimouth Plantation which is a living history museum showcasing how the Pilgrims and Wampanoag People lived in the 17th century. (Sidenote: If you need tips for planning field trips anywhere for your students I encourage you to read this helpful blog post to make organizing and managing all aspects of a field trip much easier).
I have since used this activity as a guided math lesson with small groups of students, as enrichment for my advanced math students, and as a performance-based assessment on elapsed time.
To complete the activity, students must create a schedule for a class field trip and answer related questions. They need to tell time to the minute, convert minutes and hours, calculate elapsed time, and record time both digitally and in analog form.
It’s fun and engaging…especially for your learners who enjoy project-based learning.
The packet includes:
- Task Assignment/Overview
- Thematic Paper to show their work
- Response sheets to get them explaining their thought process
- A Blank Schedule for them to complete (by recording the events, digital and analog time)
- Scoring Rubric
- Answer Key