School of the Wild maybe? Leaf rubbings are a good excuse to go outside, but you can't always find dropped leaves all year round! Use a laminator and a metal ring to create leaf rubbing plates that can be used all year long, over and over again!
This is a great idea for kids in the and grade. Have a list of materials that you have around the classroom. Have the kids go around with a magnet and see if the items are magnetic. If they are magnetic, have the