Essential Questions: What is perimeter? How does knowing the attributes of plane figures help find the perimeter of an identified plane figure? What methods are used to measure perimeter/area? How does knowing the attributes of plane figures help find the area of a figure? How is area related to multiplication and addition? What is the difference between area and perimeter? How can the area of rectilinear figures be calculated? Lesson Plans and Seeds Lesson Plan C.7a: Using Tiling to Find Area Lesson Seed C.5: Covering the Shapes Lesson Seed C.7c: Using the Distributive Property to Find the Area Lesson Seed C.7d: Area Rectilinear Download Seeds, Plans, and Resources (zip) Unit Overview Content Emphasis By Clusters in Grade 3 Progressions from Common Core State Standards in Mathematics Send Feedback to MSDE’s Mathematics Team
Lesson Plan C.7a: Using Tiling to Find Area
Lesson Seed C.5: Covering the Shapes
Lesson Seed C.7c: Using the Distributive Property to Find the Area
Lesson Seed C.7d: Area Rectilinear
Unit Overview
Content Emphasis By Clusters in Grade 3
Progressions from Common Core State Standards in Mathematics
Send Feedback to MSDE’s Mathematics Team
Lesson seeds are ideas that can be used to build a lesson aligned to the CCSS. Lesson seeds are not meant to be all-inclusive, nor are they substitutes for instruction. When developing lessons from these seeds, teachers must consider the needs of all learners. It is also important to build checkpoints into the lessons where appropriate formative assessment will inform a teachers instructional pacing and delivery.
Standard(s): 3.MD.C.7d-Recognize area as additive. Find areas of rectilinear figures by decomposing them into non-overlapping rectangles and adding the areas of the non-overlapping parts, applying this technique to solve real world problems.
Purpose/Big Idea:
Materials:
Reference:
Illustrative Mathematics – https://www.illustrativemathematics.org/3
Activity 1:
Provide Inch tiles, inch rulers, and color pencils for the following task.
Distribute Figure 1 –What is the Area?
Provide time for students to think of ways they could find the area of this figure. Prompt students to use what they have learned about finding area to find the area of this irregular shape. Suggest that students indicate by marking the shape and show the equations for finding the area.
Have students share their procedures.
Guide students to use what they know about finding areas to decompose the shape into rectangles that are not overlapping.
Discuss the various ways the shape can be decomposed into different rectangles.
Discuss the methods of solving by counting tiles, measuring with a ruler, using additive or multiplicative thinking.
Discuss which method was the most accurate and efficient.
Provide students with Figure 2- What is the Area?
Repeat the procedure above using figure 2.
Activity 2:
Provide geoboards and rubber bands, inch tiles, and about 4 pieces of inch grid paper per pair of students, and pencils (could be colored pens)
Students will work with a partner to use what they know about finding the area of rectilinear figures by creating these figures using the geoboard and rubber bands or inch tiles . One student will create the figure, the other student will draw a representation of the figure on inch grid paper and solve to find the area. The student should show how the figure was decomposed and the equations that were used to find the area of the shape. Students will discuss how their models or alike and different. If they got different answers or models students need to decide which answer is correct and why? Students switch roles and do a different rectilinear figure.
Each pair could share one figure with another partner and explain how they found the area of the shape.
Note- The student created drawings could be collected and shared as other examples to find the area.
Guiding Questions:
