Lesson 3Measuring with DifferentSized Units
Let’s measure things.
Learning Targets:
 When I know a measurement in one unit, I can decide whether it takes more or less of a different unit to measure the same quantity.
3.1 Width of a Paper
Your teacher will show you two rods. Does it take more green rods or blue rods lined up end to end to measure the width of a piece of printer paper?
3.2 Measurement Stations
Station 1
 The larger cubes are 1 cubic inch each. Count how many cubic inches it takes to completely pack the box full without gaps.
 Empty the box.
 The small cube is 1 cubic centimeter. Each rod is composed of 10 cubic centimeters. Count how many cubic centimeters it takes to completely pack the box full without gaps.
 Empty the box.
cubic inches  cubic centimeters  

volume of the box 
Station 2
 Use the meter stick to measure to the nearest meter the length your teacher has indicated.
 Use rulers to measure to the nearest foot the length your teacher has indicated.
meters  feet  

length of ______________________ 
Station 3
Watch the video. How many times can a quart bottle be filled from a gallon jug? How many times can a liter bottle be filled from a gallon jug?
quarts  liters  

1 gallon of water 
Station 4
Use the applet to record the weights of different objects in different units.
Record their weights in ounces, pounds, grams, and kilograms.
object to weigh  ounces  pounds  grams  kilograms  

object 1  
object 2  
object 3 
Station 5
 Count how many level teaspoons of salt it takes to fill the graduated cylinder to 20 milliliters, 40 milliliters, and 50 milliliters.
 Pour the salt back into the original container.
milliliters  teaspoons  

volume of salt  20  
volume of salt  40  
volume of salt  50 
After you finish all five stations, answer the following questions with your group.
 Which is larger, a cubic inch or a cubic centimeter? Did more cubic inches or cubic centimeters fit in the cardboard box? Why?
 Did it take more feet or meters to measure the indicated length? Why?
 Which is bigger, a quart or a liter? Explain your reasoning.

Use the data from Station 4 to put the units of weight and mass in order from smallest to largest. Explain your reasoning.

 If you continued filling the graduated cylinder with salt to 100 milliliters, about how many teaspoons would it take? Show your thinking.
 If you poured 15 teaspoons of salt into an empty graduated cylinder, about how many milliliters would it fill? Show your thinking.
 How many milliliters per teaspoon are there?
 How many teaspoons per milliliter are there?
Are you ready for more?
People in the medical field use metric measurements when working with medicine. For example, a doctor might prescribe medication in 10 mg tablets.
Brainstorm a list of reasons why healthcare workers would do this. Organize your thinking so it can be followed by others.
Lesson 3 Summary
The size of the unit we use to measure something affects the measurement.
If we measure the same quantity with different units, it will take more of the smaller unit and fewer of the larger unit to express the measurement. For example, a room that measures 4 yards in length will measure 12 feet.
There are 3 feet in a yard, so one foot is of a yard.
 It takes 3 times as many feet to measure the same length as it does with yards.
 It takes as many yards to measure the same length as it does with feet.
Lesson 3 Practice Problems

Decide if each is a measurement of length, area, volume, or weight (or mass).
 How many centimeters across a handprint
 How many square inches of paper needed to wrap a box
 How many gallons of water in a fish tank
 How many pounds in a bag of potatoes
 How many feet across a swimming pool
 How many ounces in a bag of grapes
 How many liters in a punch bowl
 How many square feet of grass in a lawn

Clare says, “This classroom is 11 meters long. A meter is longer than a yard, so if I measure the length of this classroom in yards, I will get less than 11 yards.” Do you agree with Clare? Explain your reasoning.

Tyler’s height is 57 inches. What could be his height in centimeters? Explain your reasoning.
 22.4
 57
 144.8

3,551

A large soup pot holds 20 quarts. What could be its volume in liters?
 7.57
 19
 21
 75.7

Clare wants to mail a package that weighs pounds. What could this weight be in kilograms?
 2.04
 4.5
 9.92
 4,500

Noah bought 15 baseball cards for $9.00. Assuming each baseball card costs the same amount, answer the following questions.
 At this rate, how much will 30 baseball cards cost? Explain your reasoning.
 At this rate, how much will 12 baseball cards cost? Explain your reasoning.
 Do you think this information would be better represented using a table or a double number line? Explain your reasoning.

Jada traveled 135 miles in 3 hours. Andre traveled 228 miles in 6 hours. Both Jada and Andre traveled at a constant speed.
 How far did Jada travel in 1 hour?
 How far did Andre travel in 1 hour?
 Who traveled faster? Explain or show your reasoning.