# Video: Finding the Volume of a Rectangular Prism by Counting Unit Cubes

Each of these rectangular prisms is made up of unit cubes. Which has a volume of 30 cubic units? [A] Figure A [B] Figure B [C] Figure C [D] Figure D.

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### Video Transcript

Each of these rectangular prisms is made up of unit cubes. Which has a volume of 30 cubic units?

To find the volume of a rectangular prism, we multiply the length times the width times the height. We have to find which rectangular prism has a volume of 30 cubic units.

Let’s start with figure A. We need to find the length, the width, and the height. The length is five units. The width is two units. And the height is three units.

Now let’s work out the volume using the formula, length times width times height. The length is five units multiplied by the width, which is two units, multiplied by the height, which is three units.

Five times two is 10. And ten multiplied by three is 30. So the volume of rectangular prism A is 30 cubic units. So the answer is figure A has a volume of 30 cubic units.