How Do Scientists Measure Things (Page 2 of 8) in pdf

LESSON

How do scientists

measure things?

How much do you weigh? What is your height? How many tiles will

cover your kitchen floor? How much milk should be added to a cake

mix? What is the temperature outside? All of these questions are

answered by measurements.

Measuring is an important part of daily life. People use measurements

all the time—for shopping, cooking, construction, and deciding how

warm to dress. Measuring also is an important part of science.

A measurement has two parts: a number and a unit. A unit is a standard

amount used to measure something.

25 liters

EXAMPLES

100

grams

number standard

number

standard

unit

There are many kinds of measurements. The most common are:

MASS and weight are related, but they are not the same. Mass is a

measure of the amount of matter in an object. Weight is a measure of the

pull of gravity on an object. The basic unit of mass in the metric system is

the kilogram (kg). Mass is measured with a balance.

LENGTH is the distance from one point to another as measured by a

ruler. The basic metric unit of length is the meter (m). You can use a

meter stick or metric ruler to measure length.

AREA is a measure of surface room—how big something is in two

directions. You can find the area of a rectangle by multiplying its length

by its width. Area is measured in square units, such as square meters (m

VOLUME is the measure of the amount of space an object takes up—

how big an object is in all three directions. The liter (L) is the basic unit of

volume in the metric system. A measuring cup or a graduated cylinder is

used to measure the volume of liquids.

The volume of a solid can be measured in cubic centimeters (cm

). You

can find the volume of a cube or rectangle by multiplying its length by

its width by its height. 1,000 cubic centimeters equals 1 liter.

TEMPERATURE is the measure of how hot or cold an object is. Temper-

ature is measured with a thermometer in degrees Celsius, (°C) or degrees

Fahrenheit, (°F). The Celsius scale usually is used in science.

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