Algebra concepts can be challenging for students in upper elementary and middle school. This lesson introduces students to the idea of a missing or unknown number while also considering the order of operations.

Facilitate rich math conversations with this lesson on finding the missing information in problems related to the area of rectangles and squares. It may be taught by itself or used as support to the lesson Finding Area: Furnishing A Room.

You need the length and the width to find the area of a rectangle or square, but what if one piece of information is missing? Use this lesson alongside What's My Area? or on its own.

Students will use the inverse relationship between multiplication and division to complete an area formula in a real-world situation. Use this lesson on its own or as support for the lesson The Case of the Missing Rectangle Side.