Apply the area and perimeter formulas for rectangles in real world and mathematical problems. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.

Students are able to…

  • Interpret scenarios to determine if you need to find area or perimeter.
  • Use the area and perimeter formulas to solve problems.
  • Apply understanding of the formulas and their relationship to one another to find missing dimensions.
  • Draw rectangles that meet given area and/or perimeter measurements.
  • Partition complex shapes into rectangles to find area/perimeter.

[divider] [/divider]Students are able to…because teachers:

  • Provide amble experiences where students have to determine if the problem is looking for area or perimeter.
  • Pose tasks that allow students to generate formulas for area and perimeter that will work for all rectangles.
  • Extend students understanding of the formula by using it to find missing dimensions.
  • Allow students to have experience where they decompose complex shapes into rectangles to find the area.

[divider] [/divider]Questions to ask students:

  • See if students describe a real world situation in which they would need to find the area or perimeter.
  • Draw a rectangle. Ask students to point and identify what you would be finding if you found the area.
    • Sample answer that indicates understanding: Area is how much space a shape covers. It’s like an array of squares so I can multiply the number of squares in a row by the number of rows.
    • Sample answer that indicates an incomplete understanding or a misconception: (while pointing to the inside) area is the inside and perimeter is the outside.
  • Ask students why the formula for area works.
    • Sample answer that indicates understanding: If I were to model this rectangle with tiles I would use ____ rows and each row would have ____ tiles. That is just like an array in multiplication!

[divider] [/divider]FSA Notes

Cognitive Complexity Level: 2 – Basic Application of Skills and Concepts

Achievement Level Descriptors:

2- applies the area and perimeter formulas when given all side measurements

3- applies the area and perimeter formulas for rectangles in real-world and mathematical problems

4- applies the area and perimeter formulas for rectangles in real-world and mathematical problems, including those where the area/perimeter and one factor (length or width) are known

5- applies the area and perimeter formulas for rectilinear shapes in real-world and mathematical problems; finds missing dimensions of rectangles when provided adequate perimeter and/or area information of the rectangle; discovers methods of maximizing area using a given perimeter, and vice versa

Assessment Limits:

Figures are limited to rectangles or composite figures composed of rectangles.

Fractions are limited to like denominators.

Limit multiplication and division to 2‐digit by 1‐digit or a multiple of 10 by 1‐digit.

Quotients may only be whole numbers.

Limit addition and subtraction to solutions within 1,000.

When constructing rectangles, one grid must be labeled with the appropriate dimension. That dimension must be “1 ____,” as items at this standard may not assess scale.

[divider] [/divider]Additional Resources:

Additional in depth content knowledge

Blog Post: Taking a Step Back to Support Students with Area and Perimeter

Video: Use area models to find the area of rectangles

[divider] [/divider]Sample Formative Assessment Tasks: