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