Help students learn and remember the parts of the skeletal system using this diagram crossword. BONUS ACTIVITY: When they've completed the crossword, get them to cut out the diagram, glue it on a separate page and label the parts of the diagram. This activity would work wonderfully within an interactive notebook as well. It can function as an assessment of learning, or it can serve as another reinforcement activity. Afterwards, they have a handy labeled diagram to help them review.