Ratio tables

Quick answer

A ratio table helps you find equivalent ratios by multiplying or dividing both parts of a ratio by the same number. You can use it to solve problems involving sharing, scaling, or comparing amounts.

Learning outcome

By the end of this page, you will be able to use a ratio table to find equivalent ratios and solve simple problems involving sharing or scaling.

• You can fill in missing numbers in a ratio table
• You can find equivalent ratios using multiplication or division
• You can use ratio tables to solve real-life problems
• You can explain how ratio tables help you compare amounts

Why this matters

Ratios help us compare amounts in a clear way. You use ratios every day when you share food, plan a party, or follow a recipe. Ratio tables make it easy to see how amounts change when you need more or less of something. This skill will help you with maths in school, cooking, shopping, and even games and sports!

How it works

A ratio table shows how two amounts are related. It has two columns, one for each part of the ratio. You start with a simple ratio, like 2 red balloons and 3 blue balloons. Then you multiply both numbers by the same amount to find more equivalent ratios.

Here's how to make a ratio table:

1. Write your starting ratio in the first row
2. Choose a number to multiply both parts by
3. Multiply both numbers in the ratio by that number
4. Write the new numbers in the next row
5. Repeat to find more equivalent ratios

Examples you can see

Let's look at a simple example using red and blue balloons:

This table shows that for every 2 red balloons, there are 3 blue balloons. If you double the red balloons to 4, you must also double the blue ones to 6. This keeps the same ratio!

Let's try another example with sandwiches and drinks:

For every 5 sandwiches, there are 3 drinks. If you have 10 sandwiches, you need 6 drinks. The ratio stays the same!

Try it as a mini adventure

Imagine you are planning a party for your class. You want to make sure everyone gets the same amount of cake and juice. You know that for every 3 children, you need 2 slices of cake and 1 glass of juice.

Here's your party planning challenge:

How many slices of cake and glasses of juice would you need for 15 children?

Answer: For 15 children, you need 10 slices of cake and 5 glasses of juice.

Common mistakes

• Mistake: Forgetting to multiply both parts of the ratio by the same number.
  Why it happens: Children might multiply one part by 2 but forget to multiply the other part.
  Fix: Always check that you multiply both numbers in the ratio by the same amount.
• Mistake: Adding instead of multiplying to find the next row.
  Why it happens: Some children think ratios work like addition.
  Fix: Remember: ratios are about multiplying or dividing, not adding or subtracting.
• Mistake: Starting with the wrong ratio.
  Why it happens: Not reading the problem carefully or misunderstanding what is being compared.
  Fix: Read the problem twice and write down the starting ratio clearly.

Parent and carer guide

Help your child understand ratio tables by:

• Using real examples from daily life like cooking or sharing snacks
• Letting them draw pictures to show how ratios work
• Practising with simple numbers first
• Encouraging them to check their work by seeing if the ratios stay the same
• Reinforcing that both parts of the ratio must change by the same amount
• Not worrying if they make mistakes - they're part of learning!

At home, you can practice with:

• Recipe scaling (if a recipe makes 4 cakes, how many for 8 cakes?)
• Sharing toys or snacks equally
• Looking at sports scores and comparing them
• Counting objects in groups and making tables

Practice questions

1. Complete this ratio table for 2 red apples and 3 green apples:

   Red apples	Green apples
   2	3
   4	6
   6	?
   8	?

   Answer: 9 green apples, 12 green apples
2. Fill in the missing numbers in this ratio table:

   Blue cars	Red cars
   5	2
   10	4
   15	?
   20	?

   Answer: 6 red cars, 8 red cars
3. What is the missing number in this ratio table?

   Yellow flowers	Purple flowers
   1	4
   2	8
   3	12
   4	?

   Answer: 16 purple flowers
4. Complete this table for 3 boys and 2 girls:

   Boys	Girls
   3	2
   6	4
   9	?
   12	?

   Answer: 6 girls, 8 girls
5. Fill in the missing values:

   Red blocks	Blue blocks
   4	5
   8	10
   12	?
   16	?

   Answer: 15 blue blocks, 20 blue blocks

FAQ

What is a ratio table?

A ratio table is a way to show how two amounts are related and how they change together. It helps you find equivalent ratios by multiplying or dividing both parts by the same number.

How do I know which number to multiply by?

You can choose any number to multiply by, but it's often easier to start with simple numbers like 2, 3, or 5. You can also work backwards from a larger number to find what you multiplied by.

Can I use division in ratio tables?

Yes! You can also divide both parts of the ratio by the same number to find equivalent ratios. For example, if you have 10 red balloons and 15 blue balloons, you can divide both by 5 to get 2 red and 3 blue.

Why do we need ratio tables?

Ratio tables help us solve problems where we need to share things equally or make more or less of something. They're useful for cooking, shopping, sports, and many other real-life situations.

How can I practice ratio tables at home?

You can practice by making tables for things like: 3 cookies for every 2 cups of flour, 4 pencils for every 1 eraser, or 5 cars for every 2 trucks. Try to find the pattern and fill in the missing numbers!