Not all roles available for this page.
Sign in to view assessments and invite other educators
Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.
The purpose of this Warm-up is to elicit what students know about length measurement and about units of measurement. While no unit is specified for the ruler in the image, students are likely to bring up centimeters (given the way each 1 unit is partitioned into 10 smaller parts, as seen on centimeter rulers). The work here prepares students to think about the relationship between meters and centimeters later in the lesson.
What do you notice? What do you wonder?
The purpose of this activity is for students to develop an intuition of 1 meter as 100 times as long as 1 centimeter. Students build a 1-meter long strip out of centimeter grid paper. They use this tool to identify objects or distances that are about 1 meter long.
Use the centimeter paper to build a strip that is 100 centimeters long. You will need scissors and tape.
If you do it precisely, your paper strip will be 1 meter long.
List 5 items in the classroom that you think are about 1 meter long.
Then use your paper strip to check how close your prediction is to 1 meter.
Decide whether each of the following is more than 1 meter, less than 1 meter, or about 1 meter.
In this activity, students analyze sample work, which shows converting meters to centimeters, to develop the understanding that a meter is “100 times as long” as a centimeter. They correct errors in reasoning, centering around place value (MP3).
Priya took some measurements in meters and recorded them in the table, but she made some errors when converting them to centimeters. She also left out 1 measurement.
| measurement (meters) | measurement (centimeters) | |
|---|---|---|
| a. height of door | 2 | 200 |
| b. height of hallway | 3 | 30 |
| c. width of hallway | 5 | 500 |
| d. length of gym | 18 | 180 |
| e. length of hallway | 27 | 2,700 |
| f. length of playground | 50 |
“Today we looked at centimeters and meters, and related them to our multiplication work.”
“Write one sentence to describe the relationship between the two units. Be specific and precise in your word choice.”
While students’ statements may emphasize the equivalence of 1 meter and 100 centimeters (“1 meter is 100 centimeters”), highlight explanations that articulate the multiplicative relationship of the two units (“1 meter is 100 times as long as 1 centimeter”).
Display the table showing Priya’s measurements. Invite students to share their responses to the last activity.
Reiterate the multiplicative relationship of the values in the two columns, revoicing students’ responses as needed. (For instance, “If 1 meter is 100 times 1 centimeter, then 3 meters must be centimeters or 300 centimeters, rather than 30 centimeters.”)