Perimeter and Area
Unit description: In this unit students will deepen their understanding of 2-D shapes by considering area and perimeter. They will focus on rectangles and how to find their area and perimeter. They will relate area to multiplication and addition. The students will develop arrays of unit squares to solve area and perimeter problems.
Download the complete Grade 3 Unit 4 framework to customize for your own planning.
Essential Outcomes of the Unit
Measurement and Data- Geometric measurement: understand concepts of area and relate area to multiplication and to addition.
- NY-3.MD.5 Recognize area as an attribute of plane figures and understand concepts of area measurement.
- NY-3.MD.6 Measure areas by counting unit squares.
- NY-3.MD.7 Relate area to the operations of multiplication and addition.
- NY-3.MD.7c Use tiling to show in a concrete case that the area of a rectangle with whole-number side length a and side length b + c is the sum of a × b and a × c. Use area models to represent the distributive property in mathematical reasoning.
- NY-3.MD.7d Recognize area as additive. Find areas of figures composed of non-overlapping rectangles, and apply this technique to solve real world problems.
Other Standards Addressed in the Unit
Measurement and Data- Geometric measurement: understand concepts of area and relate area to multiplication and to addition.
- NY-3.MD.5a Recognize a square with side length 1 unit, called “a unit square,” is said to have “one square unit” of area, and can be used to measure area.
- NY-3.MD.5b Recognize a plane figure which can be covered without gaps or overlaps by n unit squares is said to have an area of n square units.
- NY-3.MD.7a Find the area of a rectangle with whole-number side lengths by tiling it, and show that the area is the same as would be found by multiplying the side lengths.
- NY-3.MD.7b . Multiply side lengths to find areas of rectangles with whole-number side lengths in the context of solving real world and mathematical problems, and represent whole-number products as rectangular areas in mathematical reasoning.
Measurement and Data- Geometric measurement: recognize perimeter as an attribute of plane figures and distinguish between linear and area measures.
NY-3.MD.8a Finding the perimeter given the side lengths or find one unknown side length given the perimeter and other side lengths.
- NY-3.MD.8b Identify rectangles with the same perimeter and different areas or with the same area and different perimeters.
Essential Questions and Big Ideas
What is area?
Area is the amount of space a shape covers, or the measure of the inside of shape.
What is perimeter?
Perimeter is the distance around the outside of a shape.
How do we solve area and perimeter problems with rectangles?
The area of a rectangle can be determined using L x W.
The perimeter of a rectangle can be determined by using the formula 2L + 2W.
How do we find the area of a shape made of multiple rectangles?
The area of a shape made of multiple rectangles can be determined by finding the area of each rectangle using L x W and adding the total of all areas within the larger shape.
Download the complete Grade 3 Unit 4 framework to customize for your own planning.