The painted cube, step by step

A wooden block is painted all over and sawn into little cubes.

The question

How many of the small cubes have paint on exactly one face?

Where a cube sits decides how many faces are painted

block size:4
2×2=4
6×4=24
  1. A cube 4 little cubes on each side is painted all over and cut apart. We want the ones with paint on exactly one face. Nothing is counted yet.
  2. One painted face means a cube in the middle of a face, off every edge. That middle is 2 × 2 = 4 on each face.
  3. A cube has 6 faces, so 6 × 4 = 24 little cubes have one painted face.

How it works.

  1. 01

    A cube 4 little cubes on each side is painted all over and cut apart. We want the ones with paint on exactly one face. Nothing is counted yet.

  2. 02

    One painted face means a cube in the middle of a face, off every edge. That middle is 2 × 2 = 4 on each face.

  3. 03

    A cube has 6 faces, so 6 × 4 = 24 little cubes have one painted face.