Question

5.

Peggy wants to build a solid cube with a side length of 5 units. Peggy has 45 unit cubes. How many
more unit cubes does she need?

Answer 1

80

Explanation:

The cube Peggy wants to build will require 5×5×5 = 125 unit cubes. Since she has 45, she will need 80 more.

____

Peggy's cube will have 5 cubes along one edge. Then one layer will be 5 times that many, so 25 cubes. The 5 layers will be 5 times that many, so 125 cubes.