Could also connect a bunch of locks and put all the keys on a key ring. Lots of pictures of latch, lock, etc ideas for montessori type preschool. This lock one could be made with 2 boards, some o-rings, and some locks from Dollar Store.
Shadow drawing is a simple but fun outdoor art activity for kids. "In the morning a.) or late afternoon p.), place a table in a sunny spot where long shadows will be cast. Unroll paper along one side of the table, and arrange a variety of object
The bolts are graded in diameter for a more difficult exercise. Five slotted bolts and stubby screwdriver. Designed by a Montessori teacher to aid the development of eye-hand coordination and teach a practical skill.