Prealgebra for Two-Year Colleges/Workbook AIE/Measuring distances

Measuring Distances

Materials Needed: Ruler marked in inches and cm, string, scissors to cut the string

Why
When you are given a map, blueprint, or diagram, you often need to measure with a ruler to get the information you need to solve the problem.

Learning Objectives

 * 1) Use a ruler to measure perimeters (whole numbers of inches and cm).
 * 2) Use a string and a ruler to measure paths that are not straight (whole numbers of inches).

Warm-up

 * 1. Explain how to calculate the perimeter of an object.


 * Add up the lengths of all the sides.


 * 2. Which of the following objects can be used to help you measure perimeter? How?


 * Measuring cup
 * Graph paper
 * Ruler
 * 3”×5” index card
 * String
 * Sand

Activity

 * 1. Without measuring, decide which of the following shapes has the larger perimeter. Explain your reasoning.


 * [[File:Rectangle white.png]] [[File:Right polygon.png]]


 * 2. Use a ruler to measure the perimeter of the rectangle in inches.


 * 3. Use a ruler to measure the perimeter of the “H” figure in centimeters.


 * 4. Use a ruler to measure the perimeter of the triangle in inches.


 * 5. Use a piece of string and a ruler to measure the perimeter of the oval in inches.


 * 6. Use a piece of string and a ruler to measure the length of the curved path in inches.


 * 7. Use a piece of string and a ruler to measure the shortest path on the map along the highways from the bull’s eye in Antioch to the bull’s eye in Oakland in inches.


 * 4 inches, to the nearest whole inch


 * 8. If each inch on the map represents 10 miles in real life, then how far is it between the spots represented by the bull’s eyes?


 * 40 miles