2. A demonstration on how to find the volume of rectangular prisms

3. When determining the number of cubes needed to fill a rectangular prism, first find the number of cubes that will fill the bottom level.

4. Bottom Front Bottom Side

5. Can you find a quick way to find the number of cubes on the first level? Yes, multiply the number of cubes on the bottom front times the number of cubes on the bottom side. 4 units 7 units

6. Bottom Front Bottom Side So there are 28 cubes on the first level of this prism. Now all that needs to be done is take that number times the number of levels in the prism. In other words, the height of the prism.

7. 28 X 3 = 84 cubic units

8. So when calculating the volume of a rectangular prism, multiply the bottom edges to find the number of cubes on the bottom level, then multiply that number by the height to find the total number of cubes in the prism.

9. When we break this strategy down even more, it really becomes the product of the 3 dimensions of the prism. Multiplying two of the dimensions gives us the number of cubes on one level, and then multiplying by the 3 rd dimension, is multiplying by the height of the prism.

10. In our example, we multiplied the bottom front of 4, times the bottom side of 7, times the height of 3. This gave us the volume of the prism as 84 cubic units. 4 units 7 units 3 units

11. Notice that rotating the prism, will not change the volume, because you are still multiplying the same three dimensions, but just in a different order. 7 units 4 units 3 units

12. If you would like to view this tutorial again, click on the HOME button. If you are done, press the escape key.