Lesson 5: Determine the Volume of Rectangular Prisms6.GR.2

I can…

I can find the volume of a rectangular prism with whole-number edges using length × width × height.

Key words

• Volume with Whole-Number Edges — Count the unit cubes that fill the box.
• Volume — How much space is inside a solid shape.
• Rectangular prism — A box shape with six flat sides.
• Cubic units — A cube with sides 1 unit long. It measures volume.
• Length, width, height — How long, how wide, and how tall a box is.
• Net — A flat shape that folds into a solid.
• Edge — Where two flat sides of a solid meet.
• Unit cube — A cube with every edge one unit long.
• Base area — The space covered by the bottom of a solid.

Steps

1. My time capsule box is 6 long, 4 wide, and 3 tall. I write the formula: V = length × width × height.
2. I put in the numbers: V = 6 × 4 × 3.
3. First I multiply two of them: 6 × 4 = 24.
4. Then I multiply by the last one: 24 × 3 = 72.
5. So the volume is 72 cubic units. I use cubic units because volume fills space in 3 directions.

Try it

A toy box is shaped like a rectangular prism with l = 12 in, w = 3 in, h = 5 in. What is the volume?

Check your answer

180 in³

V = 12 × 3 × 5 = 180 cubic inches. Remember: volume uses cubic units (in³).

Sentence starter

I know ___ because ___.

Goal: I can explain my work using the words volume, rectangular prism, cubic units, and edge.