This lesson is usable only if these assumptions are correct. Included in the Log should be a Parts List. The children should record each experience with Lego pieces, in words or pictures or both. There is an entire unit on air in the science book.
Wind is air that is moving.
Windmills have been used by man for thousands of years for many purposes, such as grinding corn, sawing lumber, pumping water. The fourth grade students, working in groups of 2, will construct a windmill out of Lego pieces.