There's this math topic that most grades 3-5 teachers (at least) simply hate to teach. And, their students usually describe it much like they'd describe the Grinch: "a three-decker saurkraut and toadstool sandwich with arsenic sauce"--NASTY POISON! It's yucky old elapsed time!
Elapsed time is one of those topics that is just hard to "get". It's one of the skills most likely to stump students on standardized math tests (along with number & operations fact fluency, measurement, estimation, and fractions). And while there's no way we can make elapsed time as easy as basic addition, there are steps we teachers can take to make it easier to understand.
First, we need to be proactive and attack the topic of elapsed time head on. We already know from experience that this topic will trip up kids. So, let's keep it on our teacher minds all the time. This means not only planning big lessons on it, but integrating small elapsed time learning opportunities (mini & "tiny" lessons) into our plans.
One of the strategies I've always found effective is to first relate elapsed time to a child's everyday life. Kids sometimes need to see it from the practical point of view in order to comprehend this abstract concept. This full lesson that I've used in the past incorporates literature, writing, art, and math word problems. It can be taught in its entirety or broken up into mini lessons as you see fit.
Capture the kids' attention by using literature to introduce elapsed time. I like Telling Time with Big Mama Cat by Dan Harper for this purpose. This book written for ages 5-8 has a much lower reading level than for most third through fifth graders. But, I've used it anyway because the simple text makes the content easier to swallow (gulp) for kids at many levels and makes them more comfortable with the intimidating topic of elapsed time.
The book follows a day in a cat's life hour by hour (lots of naps, no doubt). After reading the story, explain that elapsed time is the time it takes Mama Cat to do something. For example, if she eats between 9 and 10 a.m., the elapsed time is one hour. (BTW, that's a S-L-O-W kitty. My dogs never lollygag like this when it comes to eating!)
Next, students can do a personalized activity that integrates math and writing to develop higher- order thinking skills. Have each child write the story of his or her day. Ask students to include start and end times when writing about different events and illustrate the times on the clock. Each page can cover a different task such as “I ate lunch from 12 to 1 p.m. We had pizza, my favorite.” Then, the student can draw himself eating pizza in the cafeteria and include a clock in the illustration with a (hopefully) correct time drawn on it.
The next day, students can revisit their books, write the elapsed time for each section, and check their work in pairs. Later, have groups of students work on elapsed time word problems. Once they can successfully solve these problems, they can write their own, and trade with a partner to solve them.
For reinforcement, I also periodically rotated hands-on activities/materials through my math centers:
- Elapsed time board games--the Race Around the Clock™ skateboarding one is WAY cool!
- Dice--for quick calculation quizzes, students can use Time Dice to roll a start and end time and then calculate the elapsed time.
- Timelines--provide students with a horizontal visual representation that allows them to easily manipulate start and end times and count elapsed time forwards and backwards.
- Clocks (duh)--but not your plain old versions. Mix it up with more unique clock formats.
- Time Tracker™ Timers--some specialized timers help kids develop a good sense of what a specific length of time feels like.