1000 small cubes are made into one cube and painted and now taken apart then how many small cubes don't have paint on all three sides?

Question asking how many small cubes without paint on three sides = the answer is 992. The big cube is 10 x 10 x 10. Only the small cubes at the corner (8 corners) get painted on three sides. Rest are either 0, 1, 2 sides painted. In sum, 1000 - 8 = 992 small cubes have less than 3 sides painted.