The volume of a cube is then (6.75cm)^3. Here the units are cubic centimeters or cm^3. Since there are 2.54 cm in 1 inch [exact] and 12 inches in 1 foot, the volume of the cube is (6.75 cm)^3 * (1 inch/2.54cm)^3 * (1 ft/12 inch)^3. 0.01086 ft^3 is your answer