# Chapter 12: Ratio and proportion

Contents

In certain situations, comparison by division makes better sense than comparison by taking the difference. The comparison by division is called the ratio of the two numbers.

## Introduction

In certain situations, comparison by division makes better sense than comparison by taking the difference. The comparison by division is called the ratio of the two numbers. In this chapter we will introduce the concept of ratios and proportions.

## Ratio

Comparing any two quantities in terms of ‘how many times’ is known as ratio, and it is denoted by a ':' sign.Two quantities can be compared only if they are in the same unit. In this topic we will learn to simplify rations, and see how they are used through several basic examples.

## Proportion

If two ratios are equal, we say that they are in proportion and use the symbol ‘::’ or ‘=’ to equate the two ratios. Here we will look into an example that should help us gain a better understanding of this topic.

## Unitary method

The method in which first we find the value of one unit and then the value of required number of units is known as Unitary Method. In this topic we will learn to use the unitary method to solve problems involving ratios.