In this unit, students learn that the area of a plane figure can be measured by determining how many square units it takes to cover the figure with no gaps or overlaps. They understand that area is measured in square units and decide on appropriate square units to use. By decomposing rectangles into rectangular arrays of squares, or by tiling rectangles, students connect area to multiplication, and justify multiplying either the length by the width or vice versa to find the area.
Key Concepts:
 Area is an attribute of plane figures describing how much twodimensional space is covered by the figure. (Lesson 1)
 Square units or unit squares (that cover a figure without gaps) can be used to measure the area of a figure, which is said to be n square units. (Lesson 2)
 We can find the area of a rectangle (with whole number length sides) by tiling it with unit squares or by multiplying the side lengths. (Lesson 7)
 Developing strategies for multiplication and division; (Grade 3, Unit 9)
Prior Knowledge Needed:
 Using arrays for foundations of multiplication; (Grade 2, Unit 13; 2.OA.4)
 Measuring length using different units; (Grade 2, Unit 2; 2.MD.A.1)
Units on the Horizon:
 Developing strategies for multiplication and division; (Grade 3, Unit 9)
 Solving problems involving area; (Grade 3, Unit 12)
 Solving problems involving shapes; (Grade 3, Unit 13)
Lessons

Lesson objective: Understand that area is an attribute of plane figures describing how much twodimensional space is covered by the figure. Students bring prior knowledge that shapes have both defining (number of sides) and nondefining (color, overall ...

Lesson objective: Understand that square units or unit squares (that cover a figure without gaps) can be used to measure the area of a figure, which is said to be n square units. Students bring prior knowledge of partitioning rectangles into equal squar...

Lesson objective: Measure the area of plane figures by counting square units. This lesson helps to build procedural skill with finding the area of plane figures. Square tiles and graph paper are used here because they support students' understanding tha...

Lesson objective: Apply understanding of measuring area by counting square units to solve problems. This lesson provides an opportunity for students to apply their knowledge and understanding of measuring area with square units to a reallife situation....

Lesson objective: Apply the skill of counting whole and half square units to estimate the area of curved figures using partial square units. This lesson provides an opportunity for students to apply their knowledge and understanding of counting square u...

Lesson objective: Reason about the size of different square units to solve area problems. This lesson provides an opportunity for students to apply their knowledge and understanding of measuring area using different square units (square inches, square c...

Lesson objective: Understand that we can find the area of a rectangle (with whole number length sides) by tiling it with unit squares or by multiplying the side lengths. Students bring prior knowledge of using repeated addition to find the total number ...

Lesson objective: Use multiplication to find the area of a rectangle and explain why tiling a rectangle with unit squares is equivalent to multiplying the side lengths. Use area models to explain the commutative property of multiplication. This lesson h...

Lesson objective: Multiply side lengths to solve word problems involving the area of a rectangle. This lesson helps to build procedural skill with using multiplication to solve word problems involving the area of a rectangle. Partitioning a rectangle in...

Lesson objective: Apply multiplying side lengths to find the area of a rectangle to solve real world problems. This lesson provides an opportunity for students to apply their knowledge and understanding of using multiplication to find the area of a rect...