Division on a slide rule involves the exact steps used in multiplication on the C and D scales, but in reverse order. Look at the graphic used earlier for 2 x 2 in step 5. To divide 4 by 2, find 4 on the D scale and place the hairline over it. Move the slider so 2 on the C scale is under the hairline. Find 1 on the C scale and the answer is directly under it on the D scale. It is 2.