Volume is the amount of space inside a 3-dimensional figure. It is measured in cubic units. A cubic centimeter is a cube that is 1 cm wide, 1 cm long, and 1 cm high.

You are watching: How many cubes are in a rectangular prism

Another way to think of volume is to find the number of unit cubes necessary for building the figure.

Suppose this is a cubic unit: How many cubic units would be needed to build this object?
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How many unit cubes are needed to build this object? | |

How many cubes are in this figure? | There are 6 cubes on the bottom "floor" There are also 6 cubes on the second "floor" And there are 6 cubes on the third (top) "floor" So, there are 18 cubes in this figure. |

Example 3 shows us that a shortcut for finding the volume of a rectangular prism is to find the number of cubes on the bottom "floor" and the multiply by the number of floors.

Volume = (number of cubes on the bottom floor) x (number of floors) Volume = Area of the base x height Volume = l • w • h |

Let"s practice this shortcut with a few more examples...

Find the volume of this rectangular prism. | Volume = (Area of the base) • (height) Volume = (4 • 3) • 5 Volume = 60 $mboxcm^3$ (If you look at each layer, there are 12 cubes in each. There are 5 layers, so that would make a total of 60 cubes.) |

Find the volume. | Volume = l • w • h Volume = 6 • 3 • 3 Volume = 36 cubic units |

Find the volume. | V = l • w • h V = 5 • 4 • 7 V = 140 units cubed |

Find the volume of this prism. | $large~24mbox u^3$ |

Find the volume. | $large~42mbox cm^3$ |

Find the volume. | $large~48mbox cm^3$ ‹ Surface area of rectangular prisms up Volume of cylinders › ## Google Matched Ad |