Formative Assessment

Can students use centimeter cubes to measure the volumes of 4 blocks?

Look for evidence that they can distinguish volume from other measurements as students use centimeter cubes to find the volumes of 4 blocks. Third grade students often confuse volume with area or height.

Keep these questions in mind as you interpret students' strategies:

• Do students take all 3 dimensions into account as they estimate the order of the blocks by volume?
• When they check their estimates, do they line up the cubes along one edge? Surround the block? Measure the height? Build a 3–D copy or replica?

To provide more experience with a difficult concept — volume is hard — a next step might be to pair students and ask them to explain their measurement strategies to each other.