Magnet Box:  Use rice with metal objects that will be attracted by a magnet. The children then use a magnetic wand to uncover all the hidden objects. (Be sure to leave room for the rice to move around or the objects will be unable to come to the surface) 

Magnet bottle: Fill the bottle half full with sand or salt. Add pins, paper clips, and small metallic objects to the sand and shake. Let the children put a small magnet on the side of the bottle and try to find hidden objects by slowly dragging the magnet.