I ask my students to save empty laundry boxes. I especially like the ones with handles. I send the boxes home with white butcher paper to be wrapped. The students and the parents wrap them so that the lid may still be opened and shut. When they're returned, I place a geometrical solid into each box and ask the children to take them home and look for things that have this same shape. They bring the objects back for everyone to observe. We discuss the shapes and the mathematical terms that are assigned to each object.