Answer:
24 cubes
Explanation:
You can figure this a couple of ways.
I usually find it easiest to figure in terms of the number of cubes each dimension represents. The vertical dimension (3/2 cm) is the length of 3 cubes; the front-back dimension (2 cm) is the length of 4 cubes, and the width (1 cm) is the length of 2 cubes.
The total number of cubes required is the product of the dimensions in cube-lengths: 3×4×2 = 24 cubes.