Lesson 2: Volume of Rectangular Prisms6.GR.2

I can…

I can find the volume of a rectangular prism, including ones with fractional edge lengths, using base area × height.

Key words

• Volume — How much space is inside a solid shape.
• Rectangular prism — A solid box shape with six flat rectangle sides.
• Cubic units — The units used to measure space inside, like cubic inches.
• Dimensions — How long, how wide, and how tall a shape is.
• Net — A flat shape that folds up into a solid.
• Base area — The area of the bottom of a solid. Volume = base area × height.

Steps

1. My capsule is 2 ft long, 1.5 ft wide, and 1 ft tall. I write V = length × width × height.
2. I put in the numbers: V = 2 × 1.5 × 1.
3. First I multiply 2 × 1.5 = 3.
4. Then 3 × 1 = 3.
5. So the volume is 3 ft³. A fractional edge like 1.5 did not change my steps at all.

Try it

A rectangular prism has l = 7 ft, w = 2 ft, h = 3 ft. What is the volume?

Check your answer

42 ft³

V = 7 × 2 × 3 = 42 cubic feet. Remember: volume uses cubic units (ft³).

Sentence starter

I know ___ because ___.

Goal: I can explain my work using the words volume, rectangular prism, dimensions, and base area.