Arithmetic Grade Five

Lesson One hundred and forty-nine: VOLUME

The volume of a three dimensional object is expressed in cubic units such as cubic feet, cubic inches, cubic meters, and so forth. To calculate the volume of a three dimensional (3D) object, you need to know three things: its height, its width, and its length. Consider this object:

This object has the following dimensions: 


        height = 8
        width  = 10
        length = 7
The light blue lines represent the lines you wouldn't usually be able to see if this box were solid.

To find the volume of the box we simply multiply the height, width, and length like this: 


      8 x 10 x 7 = 560 (cubic units)
Here's another example:

To find the volume we simply multiply the height, width, and length like this: 

     11 x 6 x 6 = 396 (cubic units)

We could also simply describe a 3D object and figure out its volume in the same way. 

     What is the volume of a box with the following dimensions:
        height: 3 inches
        width:  2 inches
        length: 5 inches

     VOLUME: 30 cubic inches

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