View video clips The goal of this lesson is for students to develop an early understanding of the concept of square root as the length of a side of a square. They begin by finding the area of a square and looking at the dimensions. Students work in pairs to find as many squares as possible that will fit in a 5x5 grid. Finding areas for squares that are not vertical to the grid is perplexing to some students. Those who have mastered the strategy share their procedure and mathematical reasoning with the class.

Together the class determines the relationship between area and side length using a variety of examples beginning with area, then beginning with side length. The teacher assesses their strategy and introduces the term square root relating the length of a side to the area of a square. A student inquires about odd numbers and numbers like five, which leads the class into an investigation of estimation strategies for finding square roots.