There are 4 cubes in the front row, 4 cubes in the middle row, and 4 cubes in the back row. Count all the cubes in the figure, 4 + 4 + 4 = 12. The volume equals 12 cubic units. Explanation

There are 4 cubes in the left row and 2 cubes in the right row. Count all the cubes in the figure, 4 + 2 = 6. The volume equals 6 cubic units. Explanation

There are 12 cubes on the bottom row and 6 cubes on top. Count the number of cubes in the figure, 12 + 6 = 18 The volume equals 18 cubic units. Explanation

There are 3 cubes on the bottom row, 3 cubes on the middle row, and 1 cube on top. Count the number of cubes in the figure, 3 + 3 + 1 = 7 The volume equals 7 cubic units. Explanation

There are 4 cubes in the left row, 1 cube in the middle, and 4 cubes in the right row. Count the number of cubes in the figure, 4 + 1 + 4 = 9 The volume equals 9 cubic units. Explanation