1. I want to display my plastic insect collection in a shadow box
I want to display my plastic insect collection in a shadow box. I need to measure them to see what size the compartments should be, but my rulers are broken? What can I do?

2. In this lesson, you will learn how to solve measurement problems by using a broken ruler.

3. You already know how to measure by using a ruler
You already know how to measure by using a ruler. Be sure to start measuring in the right place! That’s right!

4. A common misunderstanding is thinking that the number on the ruler shows the value of the hash mark. The number on the ruler actually shows the distance from the end of the ruler to the hash mark.

5. The first step is to place the end of the object you are measuring, like my grasshopper, at the end of the ruler. Notice that this ruler is broken and it STARTS at 2 inches. If the ruler isn’t broken right where a numbered hash mark is, start with the nearest one marking a whole unit.

6. Next, note the number at the end of the object
Next, note the number at the end of the object. It says 4 inches on the ruler, but I know the grasshopper is smaller than that.

7. There are at least 2 ways to figure out the length of the object
There are at least 2 ways to figure out the length of the object. You can subtract the first number from the second number: 4 minus 2 equals 2. You can also count the number of length units from one end of the object to the other. 1, 2 inches.

8. Place Note Subtract or count
Let’s measure another grasshopper in centimeters, using a ruler that is broken at the 5 centimeter mark. 1- Place the object. 2- Note the number, Subtract 10 minus 5 equals 5, or count from front to back, 1,2,3,4,5.

9. The tip of the butterfly’s antennae is at the hash mark labeled 7, and the end of the body is at minus 7 equals 7, and there are 7 centimeters between the hash marks at each end of the butterfly. Now I can measure the rest of my plastic insects for the shadow box. I wonder if the inchworm will be an inch!

10. In this lesson you have learned how to measure by using a broken ruler.