Cut a parallelogram
Kids cut a paper parallelogram, snip off a triangle from one end, and slide it to the other side. It becomes a rectangle! Ask "What stayed the same?" Doing it with their hands makes base × height make sense.
Why it works: the U.S. Department of Education's guide for teaching elementary math recommends moving from hands-on objects to drawings to numbers.
Try it withArea of Circles WorksheetWorksheetsOpen it →