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What is Ratio in Math?-EDUInput

August 4, 2022
written by Azhar Ejaz

Are you good at math? Are you good at doing mathematical calculations in your head? Do you know how to calculate the ratios in a math test? Are you good at solving problems in the subject of mathematics? If yes, then you are not alone.

Most of us know how to do this. We may not know the name of this skill, but we have it in us. It’s called mental calculation. If you want to know what the meaning of mental calculation in math is, you can learn about it in this blog post.

What is a ratio?

A ratio is an ordered pair of numbers X and Y, which can be written X/Y where Y does not equal 0. A proportion is an equation in which two ratios are set equal to each other.

image showing the ratio formula

For example

 If there is 2 boy and 3 girls you could write the ratio as 2: 3 (for every two boys there are 3 girls)

A ratio is the comparison of the parts of a whole number.

 For example

 If a whole number is 10 and the two parts are 2 and 5, then you can say that the ratio is

2 to 5. This means that the whole number is 10, and its two parts are 2 and 5.

 From Writing

To ratios

Word form

2 to 5

Colon form


Fraction form


The ratio is a comparison

  • The parking lot has six (6) cars for every three (3) trucks. Write  that has a ratio

Into word form, colon form, and fraction form.

Word form

6 to 3

Colon form


Fraction form


What is Ratio in Math?

Ratios are used to find the value of a whole number. The simplest way of doing it is to divide a number into two parts and then multiply them. In this method, you need to take care of the numbers that are not a multiple of the division number. In other words, a ratio is a relation between two quantities of some kind is called a ratio. The ratio is represented by (:) for example, 1to5 to is a ratio =1:5

Examples of ratios in math:

1 to 5 is a ratio of 1 divided by 5.

2 to 3 is a ratio of 2 divided by 3.

3 to 4 is a ratio of 3 divided by 4.

3 to 7 is a ratio of 3 divided by 7.

In the above examples, we have taken numbers that are not a multiple of the division number. So, when you divide them, you will get the correct result.

What is the purpose of ratio in math?

The use of ratios in math helps to solve the problem. It is the easiest way of finding the answer. Let us look at a simple example.


You have a circle and you want to find the area of the circle. You don’t know the radius of the circle. You have no idea whether the radius is equal to 3 cm or not. So, the first thing that you can do is to find the ratio of the diameter to the radius.

1) You divide the diameter of the circle by the radius.

2) You take an imaginary number and add it to the first number.

3) You divide the imaginary number by the first number.

4) You repeat the same process for the second imaginary number.

5) Now, you can find the area of the circle by dividing the second imaginary number by the first number.

6) Finally, multiply the first and the second number and you will get the result.

In the above example, you didn’t know the radius of the circle. But you knew the diameter of the circle. So, you calculated the ratio. And, then you got the answer by calculating the