# Lesson 2

If Our Class Were the World

Let’s use math to better understand our world.

### 2.1: All 7.4 Billion of Us

There are 7.4 billion people in the world. If the whole world were represented by a 30-person class:

• 14 people would eat rice as their main food.

• 12 people would be under the age of 20.

• 5 people would be from Africa.

1. How many people in the class would not eat rice as their main food?

2. What percentage of the people in the class would be under the age of 20?

3. Based on the number of people in the class representing people from Africa, how many people live in Africa?

### 2.2: About the People in the World

With the members of your group, write a list of questions about the people in the world. Your questions should begin with “How many people in the world. . .” Then, choose several questions on the list that you find most interesting.

### 2.3: If Our Class Were the World

Suppose your class represents all the people in the world.

Choose several characteristics about the world’s population that you have investigated. Find the number of students in your class that would have the same characteristics.

Create a visual display that includes a diagram that represents this information. Give your display the title “If Our Class Were the World.”