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S6
In Good Shape
Overview
Students interpret mathematical relationships, apply area and perimeter formulas, and
work backward through clues to figure out perimeters and areas of rectangles.
Algebra
Represent quantitative relationships with symbols • Write and solve equations
(formulas)
Problem-Solving Strategies
Work backward • Use logical reasoning
Related Math Skills
Compute perimeters of rectangles (P=l+l+w+wor P= 2 l+2w) • Compute the
areas of rectangles (A=l xw) • Recognize that opposite sides of rectangles are the
same length • Understand that squares are rectangles
Math Language
Area • Perimeter • Width • Length • Twice • Half • One-fifth •
One-fourth • One-third • Rectangle • Square
Introducing the Problem Set
Make photocopies of “Solve the Problem: In Good Shape” (page 55) and distribute
to students. Have students work in pairs, encouraging them to discuss strategies they
might use to solve the problem. You may want to walk around and listen in on some
of their discussions. After a few minutes, display the problem on the board (or on the
overhead if you made a transparency) and use the following questions to guide a
whole-class discussion on how to solve the problem:
- How can you figure out the perimeter of a rectangle? (Add the lengths of its sides.)
- What do you know about the lengths of opposite sides of a rectangle? (They are the
same length.)
- Suppose that the length of a rectangle is 3 inches and its width is 5 inches, what is its
perimeter? (3 + 3 + 5 + 5, or 16 inches)
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Algebra Readiness Made Easy: Grade 6 © Greenes, Findell & Cavanagh, Scholastic Teaching Resources