Clothespin Catapult. To make this catapult maybe involves some complex process like placing pegs in holes and putting the pieces together. It would be a great activity for older kids to make according to the directions here. http://hative.com/catapult-projects-for-kids/
math for upper grades - love this. Could give kids until Friday to answer. Thinking index cards with their name on it, and the number. Every Friday, I'll draw from the correct answers and give out money/prize. Good way to get them used to the riddles that FCAT tries to kill them with.
sorting rocks-light-medium-heavy and orange, white, gray and brown. Extend with: comparisons: bigger than, heavier than, musch smaller than and use the > < symbols to compare while weighing or balancing