Lesson 4 Measure and Estimate in Centimeters

    • Let’s estimate and measure in centimeters.

Warm-up Which One Doesn’t Belong: Length

Which one doesn’t belong?

  1. Ruler from 0 to 7, measuring length of bottom side of a triangle. Side length 4 units.
  2. Ruler, from 1 to 7, measuring length of a Rectangle.  Length of rectangle 4 units.
  3. Ruler with unevenly spaced tick marks from 0 to 7, measuring length of a rectangle. Length 4 units.
  4. Ruler, from 0 to 7, measuring length of a rectangle. Starts from 1 to 5. Length, 4 units. 

Activity 1 Estimate Length in Centimeters

  1. Notebook.

    Record an estimate that is:

    too low

    about right

    too high

  2. Notebook lying next to a 10-centimeter tool.

    Record an estimate that is:

    too low

    about right

    too high

  3. Record an estimate for each object on the recording sheet.

    Recording Sheet

    object

    estimate

    measurement

    Choose an object:

  4. Tell your partner why you think your estimates are “about right.”

Activity 2 Measure and Compare

  1. Measure each object on your recording sheet. Record each length in centimeters.

  2. Compare your measurements to your estimates.

Practice Problem

Problem 1

Here is a rectangle.

Rectangle.

  1. Estimate how many centimeters long the rectangle is.

    cm

  2. Measure the rectangle and record the measurement.

    cm

  3. How does your estimate compare to the actual length?