Science centers are a great routine to have in your classroom. These stations will help with students becoming familiar with the skeletal system. This can work for many grades! The worksheet has a copy of a labeled skeleton which can help 3rd grades learn how to use a diagram or it reinforce older students that should have some of the bones memorized.
Station 1: Labeling with sticky notes a large print out of a skeleton
Station 2: Make a model of a spinal column with play dough and pipe cleaners
Station 3: Matching game with bones and pictures of each bone