1. Unit 1: Matter & Measurement
Section 3: The Metric System

2. The Metric System
The metric system is a measurement system based on our decimal (base 10) number system.
Other countries and all scientists and engineers use the metric system for measurement.

3. Metric Prefixes Prefix Symbol Factor Number Factor Word Kilo- k 1000
The metric system has prefix modifiers that are multiples of 10.
Prefix
Symbol
Factor Number
Factor Word
Kilo- k
1000
Thousand
Hecto- h
100
Hundred
Deca-
da or dk 10
Ten
Base
m, L, or g 1
One
Deci- d .1
Tenth
Centi- c
.01
Hundredth
Milli- m
.001
thousandth

4. Place Values of Metric Prefixes
Thousand
Hundred
Ten
One
Tenth
Hundredth
Thousandth km kg kL hm hg hL
dam
dag
daL m g L dm dg dL cm cg cL mm mg mL

5. Meters Meters measure length or distance
One millimeter (mm) is about the thickness of a dime.

6. Meters One centimeter (cm) is about the width of a large paper clip
or your fingernail.

7. Meters
1 meter (m) is about the width of a doorway

8. Meters
1 kilometer (km) is about six city blocks or 10 football fields.
1.6 kilometers is about 1 mile

9. Grams Grams are used to measure
- mass (the amount of matter in an object)
- weight (the pull of gravity on an object)

10. Grams 1 milligram (mg) weighs about as much as a grain of salt.
1 gram (g) weighs about as much as a small paper clip.

11. Grams
1 kilogram (kg) weighs about as much as 6 apples or 2 pounds.

12. Liters Liters measure volume (the amount of space something occupies).
1 milliliter (mL) is approximately 20 drops from a medicine dropper or 1 sugar cube

13. Liter 1 liter (L) is half of a 2 liter bottle of soda
1 kiloliter (kL) would be about liter bottles of soda

14. Which unit would you use to measure the length of this bicycle?
Meter (m)

15. Which unit would you use to measure the mass of a penny?
Gram (g)

16. Which unit would you use to measure the water in an aquarium?
Liter (L)

17. Which unit would you use to measure the mass of a feather?
Milligram (mg)

18. Which unit would you use to measure the mass of a student desk?
Kilogram (kg)

19. Which unit would you use to measure the mass of a whole watermelon?
Kilogram (kg)

20. Which unit would you use to measure the mass of an egg?
Gram (g)

21. Which unit would you use to measure the volume of a can of soup?
Mililiters (mL)

22. Which unit would you use to measure the height of a tree?
Meter (m)

23. Which unit would you use to measure the length of a bracelet?
Centimeter (cm)

24. Metric Unit Conversions
To change from one unit to another in the metric system you simply multiply or divide by a power of 10.

25. Metric Unit Conversions
To change from a larger unit to a smaller unit, you need to multiply, or move the decimal to the right.
1 km x 1000 = 1000 m
1 m x 100 = 100 cm
1 cm x 10 = 10 mm

26. Metric Unit Conversionsg m L
103
102
101
10-1
10-2
10-3
kilo
hecto
deka
Base
unit
deci
centi
milli 1 2 3
18 L
18 liters = milliliters
Example #1: Convert 18 liters to milliliters

27. Metric Unit Conversions
To change from smaller units to larger units you divide by a power of ten, or move the decimal to the left.
1000 mm ÷ 10 = 100 cm
100 cm ÷ 10 = 10 dm
10 dm ÷ 10 = 1 m

28. Metric Conversions Example #2: Convert 450 milligrams to grams
103
102
101
10-1
10-2
10-3
kilo
hecto
deka
Base
unit
deci
centi
milli 3 2 1
450 mg = g
450 mg
Example #2: Convert 450 milligrams to grams

29. Metric Conversions Example #3: Convert 20 kilograms to milligrams
103
102
101
10-1
10-2
10-3
kilo
hecto
deka
Base
unit
deci
centi
milli 1 2 3 4 5 6
20 kg
20 kg = mg
Example #3: Convert 20 kilograms to milligrams