1. Preview
Warm Up
California Standards
Lesson Presentation

2. Warm Up
Find each value.
100
10,000
10,000
1,000,000

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

4. You can use the following benchmarks to help you understand millimeters, grams, and other metric units.

5. Additional Example 1: Choosing the Appropriate Metric Unit
Choose the most appropriate metric unit for each measurement. Justify your answer.
A. The amount of water a runner drinks each day
Liters—The amount of water a runner drinks each day is similar to the amount of water in a large water bottle.
B. The length of a boat
Meters—The length of a boat is similar to the length of several doorways.
C. The mass of a car
Kilograms—The mass of a car is similar to the mass of several hundred textbooks.

6. Check It Out! Example 1
Choose the most appropriate metric unit for each measurement. Justify your answer.
A. The amount of liquid in 10 teardrops
B. The mass of a pencil eraser
C. The length of 15 soccer fields
Milliliters—The amount of liquid in 10 teardrops is similar to the amount of liquid in several eyedroppers.
Grams—The mass of a pencil eraser is similar to the mass of several paperclips.
Kilometers—The length of 15 soccer fields is similar to the length of 10 football fields.

7. The prefixes of metric units correlate to place values in the base-10 number system. The table shows how metric units are based on powers of 10.
You can convert units within the metric system by multiplying or dividing by powers of 10. To convert to a smaller unit, you must multiply. To convert to a larger unit, you must divide.

8. Additional Example 2A: Converting Metric Units
Convert the measure.
530 cL to liters. 100cL = 1L
100 cL = 1L, so divide by 100.
530 cL = (530 ÷ 100) L
Move the decimal point 2 places left: 5.30.
= 5.3 L

9. Additional Example 2B: Converting Metric Units
Convert the measure.
1,070 g to milligrams 1g = 1000mg
1 g = 1000 mg, so multiply by 1000.
1,070 g = (1,070  1,000) mg
Move the decimal point 3 places right: 1,
= 1,070,000 mg

10. Check It Out! Example 2A
Convert the measure.
980 dm to meters 10 dm= 1 m
10 dm = 1m, so divide by 10.
980 dm = (980 ÷ 10) m
Move the decimal point 1 place left: 98.0.
= 98 m

11. Check It Out! Example 2B
Convert the measure.
580 g to centigrams 1g = 100cg
1 g = 100 cg, so multiply by 100.
580 g = (580  100) cg
Move the decimal point 2 places right:
= 58,000 cg

12. Additional Example 3: Using Unit Conversion t to Make Comparisons Eliza buys one pumpkin that has a mass of 3 kg and another that that has a mass of 2,150 g. Which pumpkin has the greater mass? Use estimation to explain why your answer makes sense.
You can convert the mass of Eliza’s pumpkin to grams.
1 kg = 1000 g, so multiply by 1,000.
3 kg = (3  1,000) g
Move the decimal point 3 places right:
= 3,000 g
Since 3,000 g > 2,150 g, the 3 kg pumpkin has the greater mass.

13. Additional Example 3 Continued
Eliza buys one pumpkin that has a mass of 3 kg and another that that has a mass of 2,150 g. Which pumpkin has the greater mass? Use estimation to explain why your answer makes sense.
Check
Use number sense. There are 1,000 grams in a kilogram, so the mass of the other pumpkin is about 2,000 g or 2 kg. 3 kg > 2 kg, so the answer is reasonable.

14. Check It Out! Example 3
Tyesha purchases a bag of potatoes that has a mass of 2.5 kg and Casey purchases a bag with a mass of 3,850 g. Which bag of potatoes has the greater mass?
You can convert the mass of Tyesha’s bag to grams.
1 kg = 1000 g, so multiply by 1,000.
2.5 kg = (2.5  1,000) g
Move the decimal point 3 places right:
= 2,500 g
Tyesha’s 2,500 g bag of potatoes has a smaller mass.

15. Check It Out! Example 3 Continued
Tyesha purchases a bag of potatoes that has a mass of 2.5 kg and Casey purchases a bag with a mass of 3,850 g. Which bag of potatoes has the greater mass?
Check
3,850 g is about 4000 g or 4 kg. 4 kg > 2.5 kg, so the answer is reasonable.

16. Lesson Quiz Convert each measure. 1. 1,270 g to kilograms
cm to millimeters
mL to liters
km to meters
mg to grams
1.27 kg
8,900 mm
0.75 L
122,000 m
0.8 g
6. Rosa walks 1.5 km to the library. Meghan walks 2,200 m to the library. Who walks farther? Use estimation to explain why your answer makes sense.
Meghan walks farther. 2,200 m = 2.2 km