After reading the story The Mitten, it's fun to figure out how all those animals could have fit in that tiny mitten. Let students explore the volume of real mittens by filling them with unifix cubes until they can hold no more. Then students can count the manipulatives as they remove them from the mitten. Continue with other manips. to compare.
Area can be explored in a similar way by drawing a 2-D mitten on a paper and having the children fill in the area with one type of manip. Explore with other manips. as well to compare.