What's the Math in This Chapter?

Math Domain: Measurement and Data (MD)

Mathematical Practice Standard: Look for and make use of structure. (MP7)

Most of this chapter concentrates on the Measurement and Data (MD) domain. 

As students explore more about the different aspects of perimeter and area, they will understand that there is a relationship between the side lengths of a rectangle and its perimeter and area.  By using models and tiliing, students may notice patterns that will help them trnasition more easily into using formulas for perimeter and area of rectangles.

What should students already know?

In the previous grade, students used Geometry (G) in the their study of area:

• Partition a rectangle into rows and columns of same-size squares and count the squares to find area. (2.G.2)

What students should understand and be able to do:

• How to find the perimeter of a figure.

  • Add side lengths to find teh perimeter.

• How to find the area of a figure.

  • Area is measured in square units.

  • A figure that can be covered by n unit squarese with no gaps or overlaps has an area of n square units.

• How to tile a rectangle to find the area.

  • If a rectangle is not on a grid, the area can be found by tiling it.

  • The dimensions of a rectangle are called its length  width.

• How to use a formula to find the area of a rectangle.

  • To find the area of a rectangle, multiply the length by the width.

  • The formula is A = L x W.

• How to decompose a composite figure to find the area.

  • A composite figure is made up of two or more figures.

  • Find the area of a composite figure by decomposing it into smaller rectangles and then adding the area of each rectangle.

• How to relate perimeter and area of rectangles.

  • Two rectangles can have the same perimeter and different areas, or have the same area and different perimeters.

What will students do next with these skills?

• In Grade 4, students will learn to find the width of a rectangle given the area.

From Reflex's website:

"Reflex makes it easy to get students math fact fluent and ready for more complex math.  Assessment, coaching, and practice is delivered via a fun, game-based approach. And because it is fully adaptive, students get the individualized instruction they need to be successful."