# Surf for More Math

## CHAPTER 5: MEASUREMENT

**Lesson 4: Calculating Circumference **

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**

Apply the formula for the circumference of a circle using ¶ (Pi).

**Builds Upon**

Student book pages 208–213

**Instructions for Use**

**Challenge Exercises: Circumference of a Circle** allows students to practice finding the circumference, diameter, and radius of a circle.

Read through the explanation of the number ¶ (Pi) and the formula for calculating the circumference of a circle, look at the example questions, and then scroll down to the Exercises. Solve each problem and type your answer into the blank text box. Click the “Enter” button to check each answer.

**Calculating the Circumference of a Circle** allows students to practice finding the circumference of a circle.

To use Calculating the Circumference of a Circle, read the instructions for calculating circumference of a circle at the top, and then scroll down to the practice section. Click the “Start” button to get a problem, and type your answer in the blank text box. Click the “Check” button to check each answer. The activity will keep track of how many correct answers you give.