The Dog Interview

Ben and Julie's parents have some questions for them before they will be able to get a dog. Meanwhile, Hesed, the husky, also has questions about his new home. Will Ben and Julie pass the dog interview? The mathematics of area, perimeter, and geometry are incorporated in this wonderful book.

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The relationship between area and perimeter
Area, the two-dimensional space inside a region, and perimeter, the distance around a region, are continually a source of confusion for students. This is in part because students may simply be given formulas to use and not understand the concept of area and perimeter. The two activities below are useful to help students understand area and perimeter.

Activity #1
Give students a loop of non-stretching string that is exactly 24 centimeters in circumference. The task is to decide what different-sized rectangles can be made with a perimeter of 24 cm. Students can be given 1 cm grid paper to place their string on. Each different rectangle can be recorded by students with the area calculated.  Students can also do this activity with just the grid paper by being asked to find rectangles with perimeters of 24 cm.

Activity #2
Provide students with centimeter grid paper. The task is to see how many rectangles can be made with an area of 36 cm squared. Each new rectangle should be recorded by sketching the outline and the dimensions on grid paper. For each rectangle, students should determine and record the perimeter as well.