[DonRotolo]

Legos and a movie - aimed at younger middle-schoolers, they see an age-appropriate movie and get to build a lego creation.

For older students, an egg drop. They get 8' of twine, 3 napkins, 2 sheets of paper, 6 soda straws and a roll of scotch tape. And an egg. Whose contraption can drop furthest without breaking? (Modify the materials and quantities as desired. Have a place you can drop 30 feet, it can come to that).

Soda-bottle rockets. 2 soda bottles, scissors and tape. Put water in the bottle, add compressed air*, whose goes furthest? *You will need to build a bicycle-pump-powered inflator with release mechanism. Google it.