Lesson 3 Create and Use a Ruler

    • Let’s create rulers and use them to measure and compare lengths in centimeters.

Warm-up Number Talk: Subtract Two Digits

Find the value of each expression mentally.

Activity 1 Create a Ruler

  1. Use your tools to make a ruler that shows lengths in centimeters.

  2. Compare your ruler with your partner’s ruler.

Activity 2 Measure and Compare Lengths

Problem 1

Use your ruler to measure the length of each rectangle. Don’t forget to label your measurements.

  1. Rectangle.
  2. Rectangle.
  3. Rectangle.
  4. Rectangle.
  5. Rectangle.
  6. Rectangle.

Problem 2

How many centimeters longer is rectangle a than rectangle b?

Problem 3

How many centimeters longer is rectangle f than rectangle d?

Problem 4

Which two rectangles are the longest? How long would the rectangle be if you joined them together?

Practice Problem

Problem 1

How many centimeters long is each side of the triangle? Label each side.