Students will be able to describe the concept of elapsed time.
- Introduce the concept of elapsed time to your students by explaining that elapsed time means that time passes, or goes by.
- Ask students to share some examples of elapsed time. Some guiding questions you can ask are: "How much time has elapsed since you woke up? How much time elapses while you eat lunch?"
Explicit Instruction/Teacher modeling(20 minutes)
- On the board, draw a number line (six ticks) with arrows at both ends. Label each tick with the following times (pm): 1:00, 2:00, 3:00, 4:00, 5:00, 6:00. Let students know you drew a timeline. Explain that a timeline shows different times from earliest to latest.
- Ask students to think about what they do at the earliest time written on the timeline, 1:00pm. Remind students that pm means in the afternoon and am means in the morning.
- Allow a few students to share out their ideas and jot them on the board. Ideas may include: I'm at school, I'm in math class, etc.
- Point to the latest time on the timeline, 6:00pm. Ask students to think about what they usually do around 6:00pm. Ideas may include: I eat dinner with my family, I play outside, etc.
- Show students how to "jump" by hour. For example, you could go from 1:00pm to 2:00pm by jumping one hour forward (show this as a hump, or upside down U). To go one hour back from 2:00pm to 1:00pm, you would jump one hour backward.
Guided Practice(20 minutes)
- Put students in partnerships and distribute an analog clock to each pair.
- Ask students to get out their math journals. Have students draw their own timelines in their math journals, using yours as a model.
- Write down the following story problem: "Ms. Brown left school at 3pm. She got to her house at 4pm. How long did it take Ms. Brown to get home? How much time elapsed, or passed, from the time she left school to the time she arrived home?"
- Remind students to use the timeline to mark the jumps and calculate the amount of time that passed from leaving school to arriving home.
- Repeat this exercise with two more meaningful story problems that ask students to calculate elapsed time going forward or going back.
- Ask partnerships to share their ideas aloud with the rest of the class.
Independent working time(30 minutes)
- Write two more word problems that involve elapsed time on the whiteboard (make sure they are meaningful and relevant to all students).
- Provide students with time to complete the word problems, reminding them to use their analog clocks and timelines for support.
- Walk around and observe students as they work. Provide assistance when needed.
Enrichment: See if students can come up with their own word problems involving elapsed time to the hour. Instruct students to exchange their word problems with a peer and complete them.
Support: Allow students to work in small, teacher-led groups or partnerships during independent working time.
- Take notes about common mistakes and use them to design future lessons on exploring elapsed time.
- Collect math journals at the end of the lesson and review them.
Review and closing(10 minutes)
- Briefly review the concept of elapsed time.
- Go over the answers to the word problems, pausing occasionally to ask about difficulties that students came across.
- Use the remaining time to answer any questions students have about the lesson content.