Chapter 5: Functions and relationships (Part 1)
5.1 Introduction
In this chapter, you will learn about quantities that change. It is often the case that when one quantity changes, another quantity also changes. For example, as you make more and more calls on a phone, the total cost increases. In this case, we say there is a relationship between the number of calls you make and the amount of money you must pay. You will learn how to describe a relationship between two quantities in different ways: using flow diagrams, tables and equations.