7th Grade Science Student ebook

1.1 MEASUREMENTS

Chapter 1: Studying Life

The International System of Measurement (SI)

Units allow people to communicate amounts. To make sure their

measurements are accurate, scientists use a set of standard units

that have been agreed upon around the world. Table 1.1 shows the

units in the International System of Measurement, known as the

SI.

Table 1.1: Common SI Units

Quantity Unit Value

Length

meter (m)

kilometer (km)

decimeter (dm)

centimeter (cm)

millimeter (mm)

micrometer (μm)

nanometer (nm)

1 km = 1,000 m

1 dm = 0.1 m

1 cm = 0.01 m

1 mm = 0.001 m

1 μm = 0.000001 m

1 nm = 0.000000001 m

Volume cubic meter (m (^3) )
cubic centimeter (cm^3 )
liter (L)
milliliter (mL)
1 cm^3 = 0.000001 m^3
1 L = 0.001 m^3
1 mL = 0.001 L
Mass kilogram (kg)
gram (g)
milligram (mg)
1 g = 0.001 kg
1 mg = 0.000001 kg
Temperature
Kelvin (K)
Celsius (°C) 0°C = 273 K100°C = 373 K
The United States uses the English
system of measurement. This
system uses miles, yards, feet,
and inches for length. Conversion
factors are useful in converting
from English to SI and back again.
For example,
1 inch = 2.54 cm.
Use this conversion factor to solve
the following problems. The first
one is done for you.

1. 10 in. × (2.54 cm/1 in.) =
   25.4 cm.


2. 0.50 in. = _____ cm


3. 300 cm = _____ in.


4. 1 m = _____ in.


5. 2 km = _____ in.