Teaching Models

Metric Measurement

The metric system of measurement is based on 10 and powers of 10. The prefixes used for length, capacity, and mass tell what part of the basic unit is being considered.

kilo-
hecto-
deka-
deci-
centi-
milli-
1,000
100
10
0.1
0.01
0.001
kilo-
hecto-
deka-
deci-
centi-
milli-
k
h
da
d
c
m
as in km for kilometers
as in hm for hectometers
as in dam for dekameters
as in dm for decimeters
as in cm for centimeters
as in mm for millimeters

At this grade level, the only prefixes that will be used are kilo-, deci-, centi-, and milli-.

The common units of length include millimeters, centimeters, decimeters, meters, and kilometers. Students should know the following equivalencies and abbreviations. Remind students that abbreviations do not take a plural s.

Length
100 centimeters (cm) = 1 meter (m)
10 decimeters (dm) = 1 meter (m)
1,000 meters (m) = 1 kilometer (km)

In the metric system of measurement, the common units of measure and abbreviations for capacity and mass* are shown below. Students should know the following equivalencies and abbreviations.

Capacity
1,000 milliliters (mL) = 1 liter (L)
Mass
1,000 grams (g) = 1 kilogram (kg)

*Note that the metric system most commonly uses a measure of mass rather than weight. These terms are often used interchangeably, but there is a difference. Mass measures the amount of matter in an object. Weight measures the gravitational pull on the object. In space, an astronaut who is “weightless” still has the same mass as on Earth.


Teaching Model 14.2: Meter and Kilometer


Houghton Mifflin Math Grade 3