### Metric Units of Length, Mass, and Capacity

```Metric Units of Length, Mass,
and Capacity
Lesson 9-1
The Metric System
• The metric system of measurement is a
decimal system that uses prefixes to
relate the sizes of units to standard units.
• The standard unit of length is the meter.
• The standard unit of mass is the gram.
• The standard unit of capacity is the liter.
Metric Prefixes
kilo
hecto
deka
deci
centi
milli
1,000
100
10
0.1
0.01
0.001
Length (distance)
The standard unit is a meter. A meter is about the
distance from the floor to the doorknob on a door.
1,000 meters make a kilometer. It is roughly 0.6 of
a mile long. To run a kilometer, you would have to
run around a track two and a half times.
A centimeter is smaller than a meter. It takes 100
centimeters to make a meter. The thickness of a
CD case is about 1 cm.
A millimeter is very small. It takes 1,000 mm to
make a meter. The thickness of a CD is about 1
mm.
Measuring
Metric rulers show centimeters and millimeters.
Line up the zero (or edge of the ruler if there is no
zero) with the edge of what you’re measuring.
The line is 5.3 cm long. You could also read it as 53 mm.
Mass – the amount of matter
that an object has.
The standard unit is a gram. A gram is about the
mass (or, basically, the weight) of a paper clip.
1,000 grams make a kilogram. You would use
kilograms to measure heavier things, like desks
and people. A kilogram is roughly equivalent to the
weight of a one liter bottle of water. A newborn
A milligram is very small. It takes 1,000 mg to
make a gram. An eyelash weighs about 1 mg.
Capacity – the amount of liquid
an object holds.
The standard unit is a liter. A bottle of juice holds