Math Focus 7

# Surf for More Math

## CHAPTER 5: MEASUREMENT

### Lesson 6: Calculating the Area of a Circle

Use these interactive activities to encourage students to have fun on the Web while learning about measurement. Students can try these activities on their own or in pairs.

Goal

Develop and apply the formula for the area of a circle.

Builds Upon

Student book pages 216–219

Instructions for Use

Interactive Area of a Circle allows students to explore the relationship between area, radius, and circumference of a circle.

Click and drag a point on the circle. Note how the calculation for area changes when the radius of the circle changes. Recall that the raised 2 after the r means that r is multiplied by itself (r2 = r × r).

Calculating Areas is an online quiz that allows students to practice calculating the area of a variety of shapes, including circles.

Take this online quiz to show how you are able calculate the area of a variety of shapes. Find the solution to each problem using a paper, pencil and a calculator. Then select your answer from the options given (A, B, C or D). Click the “Check It” button at the end of the quiz to check your answers.