Number the true ribs consecutively one to seven, starting at the topmost true rib and continuing downward toward the skeletal feet bones. These ribs are connected to the sternum by strips of cartilage.
Number the false ribs consecutively eight to 10, beginning at the false rib closet to the seventh true rib and continuing downward toward the skeletal feet bones. These ribs are attached to the seventh true rib and do not attach directly to the sternum.
Number the floating ribs consecutively 11 to 12, beginning at the floating rib closet to the 10th false rib and continuing downward toward the skeletal feet bones. These ribs are attached to the spine.