1. Preview
Warm Up
California Standards
Lesson Presentation

2. Warm Up
Simplify. 4 16 1 4 9 16 9 16 1. 2. 6 8 3. 3 4 14 16 4. 7 8

3. California
Standards
AF2.1 Convert one unit of measurement to another (e.g., from feet to miles, from centimeters to inches).
Also covered: NS1.3

4. Objective: You will learn how to identify and compare customary units of measurement.

5. You can use the following benchmarks to help you understand fluid ounces, tons, and other customary units of measure.

6. Example 1: Choosing the Appropriate Customary Unit
Choose the most appropriate customary unit for each measurement. Justify your answer.
A. the weight of a car
tons; The weight of a car is similar to the weight of a buffalo.
B. the diameter of a soap can
inches; The diameter of a soup can is similar to the length of a few paper clips.
C. the weight of a newborn baby
pounds; The weight of a newborn baby is similar to the weight of more than a dozen apples.

7. Check It Out! Example 2
Choose the most appropriate customary unit for each measurement. Justify your answer.
A. the length of a pen top
inch; The length of a pen top is similar to the length of a small paper clip.
B. the weight of a pitcher of juice
pounds; The weight of a pitcher of juice is similar to the weight of about 10 apples.
C. the capacity of a jar of peanut butter
cups; The capacity of a jar of peanut butter is similar to the capacity of 2 standard measuring cups.

8. Length Weight Capacity
12 inches (in.)= 1 foot (ft)
3 feet = 1 yard (yd)
5,280 feet = 1 mile (mi)
Weight
16 ounces (oz) = 1 pound (lb)
2000 pounds = 1 ton
Capacity
8 fluid ounces (fl oz) = 1 cup (c)
2 cups = 1 pint (pt)
2 pints = 1 quart (qt)
4 quarts = 1 gallon (gal)

9. Example 3: Converting Customary Units
Convert 5,000 pounds to tons.
Method 1: Use a Proportion.
Write a proportion using a ratio of equivalent measures.
pounds tons
2,000 1
5,000 m x =
2,000 • x = 1 • 5,000
2,000x = 5,000
x = 2.5
5,000 pounds is equal to 2.5 tons.

10. Example 3 Continued
Convert 5,000 pounds to tons.
Method 2: Multiply by 1.
Multiply by a ratio equal to 1, and cancel the units.
5,000 lb m 1
1 ton t 2,000 lb
5,000 lb = 
1 ton t 2,000
= 5,000 
= 2.5 tons
5,000 pounds is equal to 2.5 tons.

11. Check It Out! Example 4
Convert 24 pints to cups.
Method 1: Use a Proportion.
Write a proportion using a ratio of equivalent measures.
cups pints
2 1
c 24 =
1 • c = 2 • 24
c = 48
24 pints is equal to 48 cups.

12. Check It Out! Example 4 Continued
Convert 24 pints to cups.
Method 2: Multiply by 1.
Multiply by a ratio equal to 1, and cancel the units.
24 pt m1
2 ct 1 pt
24 pt = 
2 c 1
= 24 
= 48 cups
24 pints is equal to 48 cups.

13. Example 5: Converting Between Metric and Customary Units
One mile is about 1.6 kilometers. What is the length in miles of a 10 kilometer race? Round to the nearest tenth of a mile.
miles kilometers
x 10
Write a proportion using mile  1.6 kilometers. =
1.6 · x = 1 · 10
The cross products are equal.
1.6x = 10
Multiply.
1.6x
1.6 10
1.6 =
Divide each side by 1.6.
x  6.3
Round to the nearest whole number.
The length of a 10 kilometer race is about 6.3 miles long.

14. Check It Out! Example 6
One cup is about 8 fluid ounces. What is the amount in cups of a 35 fluid ounce container? Round to the nearest tenth of a cup.
cups fluid ounces
1 8
x 35
Write a proportion using cup = 8 fluid ounces. =
8 · x = 1 · 35
The cross products are equal.
8x = 35
Multiply. 8x 8 35 8 =
Divide each side by 8.
x  4.4
Round to the nearest whole number.
The amount of a 35 fluid ounce container is about 4.4 cups.

15. Home Learning

16. Lesson Quiz: Part I
Choose the most appropriate customary unit for each measurement. Justify your answer.
1. the capacity of a bathtub
2. the weight of a calculator
3. the length of an indoor sports arena
gallons; similar to the capacity of several large milk jugs
ounces; similar to the weight of several slices of bread
too small to measure in miles, so it should be measured in feet

17. Lesson Quiz: Part II
4. Convert 13 gallons to quarts.
5. One ounce is about 28.3 grams. A box of cereal has a mass of 400 grams. What is the weight of the box in ounces? Round to the nearest tenth of an ounce. 52
14.1 oz