Volume is the amount of space that an object takes up. We can measure volume with unit cubes, like the one below.

These are called unit cubes because each one represents cubic unit. The volume of a figure is the number of unit cubes that make it up.

For example, let's find the volume of the figure below:

The figure consists of cubes.

Therefore, its volume is cubic units.

We can use metric and customary units to measure volume.

Consider the cube below, whose length, width, and height all equal centimeter.

Since the length, width, and height of this cube all equal centimeter, the volume of this cube is cubic centimeter.

Commonly used metric units of volume are:

• cubic meters

• cubic centimeters

• cubic millimeters

Commonly used customary units of volume are:

• cubic feet

• cubic inches

We'll learn more about units of volume in future lessons.

If a figure has multiple layers, we can find its volume by first finding the volume of each layer and then adding the results.

Each cube in the figure below represents one cubic unit. Let's find its volume.

The figure consists of two layers:

• The bottom layer consists of cubes.

• The top layer consists of cubes, too.

Therefore, the volume is cubic units.