Proportion And Ratio (KS2) Made Easy For Parents

One of the many topics covered in KS2 maths is proportion and ratio.

If you have children in school years three to six, you will most likely be asked questions about all about proportion and ratio. This guide is here to make sure you can help!

It contains definitions, explanations, problems and resources to help your children learn everything they need and for you to be able to answer all of their questions.

If you are in need of more resources to help you navigate your children's KS2 maths curriculum, take a look at this guide to translations explained for parents or at this list of maths homeschool resources for KS2 and KS3.

The ratio between two values shows you how much of one thing there is compared to another. They are generally written in this form:

Value A : Value B

Ratios are useful to determine how many time one value is contained in another. For example, if you are making a hot chocolate in which you mix one part of cocoa powder to six parts of mix, your ratio of cocoa powder to milk will be 1:6, which is pronounced "one to six".

The order of the values in a ratio are very important; if they are reversed, then so are the proportions!

There are a total of four ways to write a ratio:

• By using a colon, like 10:40.
• By simplifying it, for example 10:40 becomes a ratio of 1:4 if you divide both sides by 10.
• By writing it out as a sentence, for example a ratio of 10:40 is a ratio of ten to forty, meaning for ten parts of one thing, you have forty parts of the other.
• By translating it into a fraction, for example 10:40 is 10/40.

You can simplify a ratio if the values on either side of the : can be divided by the same number. For example, 6:9 can be simplified by dividing six and nine by three, which gives a ratio of 2:3.

The rule which says that 6:9 and 2:3 are equal is called proportion. If two ratios are the same, they are proportional, which means their relative sizes are the same.

In other words, if your hot chocolate has six parts cocoa and nine parts milk, there is relatively the same amount of cocoa to milk than in a hot chocolate with two parts cocoa and three parts milk.

At KS2 level, children should understand the concepts of ratio and proportion and be able to use and explain them easily.

They should also be able to simplify a ratio and to use it to compare values or quantities.

Children in Year 6 should be able to convert a ratio into a fraction, and vice versa.

In order to assess your child's understanding of ratio and proportion, they will most likely be tested using problems and questions. The idea will be to use the concepts they have learned to solve worksheets.

Many of the proportion and ratio questions KS2 children face can be difficult but with lots of practice, and a bit of help from you, they will get there! Here are some ideas of fun activities and resources to help your children learn about the concepts of ratio and proportion.

1. Write a list of ratios and get your child to practice enunciating them, and converting them into fractions.

2. Find recipes with round values or amounts that are easy to double and divide. If you can't find any, invent one! Say the recipe is meant for four people, ask your child to tell you the quantities necessary for one or eight people. Make sure all the values they indicate are proportional!

3. There are plenty of ratio and proportion worksheets available online. Download and print some to give to your child to complete, there could be a reward or a gold star in it for them! If you are feeling creative, create your own ratios and proportions worksheet.

4. Create some problems for your child to solve using ratios and proportionality. Here is an idea to get you started:

Jonny is making squash for himself. He adds 10ml of squash to 100ml of squash. Three friends of Jonny's come along and want some squash too.

a) What is the ratio of squash to water that Jonny uses for himself?

b) How much squash and water are needed to make squash for three people, adapting Jonny's recipe proportionally? Express it as a ratio, and simplify it.