1. Metric System prefixes
Using the International System of Units

2. Metric unit helpful hint
To memorize the six prefixes you really need to know, remember this sentence:
King Henry Doesn’t Usually Drink Chocolate Milk

3. Metric unit helpful hint
If you look closely, you will see that each prefix is ten times bigger than the one to its right and one-tenth as big as the one to its left.

4. On your prefix line, write the number above the prefix and place your finger under the prefix.

5. Count the number of units your finger passes while moving to the unit you’re converting.

6. Take your number, and move the decimal point the same number of places in the same direction.

7. Take your number, and move the decimal point the same number of places in the same direction.

8. Add a 0 for each place the decimal moves.

9. There you have it: 5 hectograms is the same as 500,000 milligrams.

10. Example #1- How many milliliters are in 2 liters?
___ ___ ___ ___ ___ ___ ___
Kilo Hecto Deka Unit Deci Centi Milli
Liter
2 liters = 2000 milliliters
2 L = 2000 mL 2.

11. Example #2- How many grams are in 8 kilograms?
___ ___ ___ ___ ___ ___ ___
Kilo Hecto Deka Unit Deci Centi Milli
Gram
8 kilograms = 8000 grams
8 kg = 8000 g 8.

12. Example #3- How many meters are in 4 centimeters?
___ ___ ___ ___ ___ ___ ___
Kilo Hecto Deka Unit Deci Centi Milli
Meter
4 centimeters = 0.04 meters
4 cm = 0.04 m 4.

13. 6.5 kg = ________g
1.42 m = _____ cm
3.6 L = _____ml
12.85 ml = _____L

14. Compare. Write <,>,or=
6.2 L _____ 620 ml
2.6 meters ____ 26,000 cm

15. You can use the information in the table below to convert one customary unit to another.
When you convert one unit of measure to another, you can multiply by a conversion factor.

16. Example 1: A. Using a Conversion Factor
Convert 9 yards to feet.
Set up a conversion factor.
Think: yards to feet–3 feet = 1 yd, so use
3 ft 1 yd
3 ft 1 yd
Multiply using the conversion factor. Cancel the common unit, yd.
9 yd 
9 yd = 27 ft
Write the unit you are converting to in the numerator and the unit you are converting from in the denominator.
Caution!

17. Example 1B: Using a Conversion Factor
Convert 10,000 pounds to tons.
Set up a conversion factor.
Think: pounds to tons–1 ton = 2,000 lbs, so
use
1 ton s 2,000 lbs
Multiply 10,000 lbs by the conversion factor. Cancel the common unit, lbs.
1 ton 2,000 lb
10,000 lb 
10,000 lb = 5 tons

18. Example 2: B. Converting Units of Measure by Using Proportions
Convert 3 quarts to cups.
Convert quarts to cups.
3 qt = cups
1 quart is 4 cups. Write a proportion. Use a variable for the value you are trying to find.
1 qt 4 c
3 qt x =
1 • x = 4 • 3
The cross products are equal.
1x = 12
Divide both sides by 1 to undo the multiplication.
x = 12
3 quarts = 12 cups.

19. Example 2B
Convert 144 cups to gallons.
Convert cups to gallons.
144 cups = gallons.
1 gallon is 16 cups. Write a proportion. Use a variable for the value you are trying to find.
1 gal 16 c
x c =
16 • x = 1 • 144
The cross products are equal.
16x = 144
Divide both sides by 16 to undo multiplication.
x = 9
144 cups = 9 gallons.

20. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

21. Lesson Quiz
1. Convert 5 yards to inches.
2. Convert 16 tons to pounds.
3. Convert 11 quarts to cups.
4. A project requires 288 inches of tape. How many yards is this?
180 inches
32,000 pounds
44 cups
8 yards

22. Lesson Quiz for Student Response Systems
1. Which of the following represents 7 yards in inches?
A. 252 in. B. 245 in.
C. 238 in. D. 231 in.

23. Lesson Quiz for Student Response Systems
2. Which of the following represents 12 tons in pounds?
A. 12,000 pounds B. 36,000 pounds
C. 24,000 pounds D. 40,000 pounds

24. Lesson Quiz for Student Response Systems
3. Which of the following represents 14 quarts in cups?
A. 196 cups B. 112 cups
C. 84 cups D. 56 cups

25. Lesson Quiz for Student Response Systems
4. An electrician requires 324 inches of electrical wire. How many yards is this?
A. 7 yards B. 8 yards
C. 9 yards D. 10 yards