Thirds for children

Quick answer

Thirds are when you split something into three equal parts. Each part is one-third of the whole. It doesn't matter how the pieces look – they must be the same size!

Learning outcome

By the end of this page, you will understand that thirds mean three equal parts, and you can identify and share things equally into thirds.

• You can split a shape or object into three equal parts
• You can say which part is one-third
• You can share items equally among three people
• You can explain why pieces must be the same size to make thirds

Why this matters

Fractions like thirds help us share things fairly. Whether you're splitting a cake, dividing a pizza, or sharing toys, understanding thirds makes sure everyone gets a fair piece. It’s also the beginning of learning more complex fractions like halves, quarters, and fifths. Thirds are used in cooking, art, music, and even in sports when you split a team into three groups!

How it works

Let’s imagine you have a chocolate bar and want to share it with two friends. That means you need to split it into three equal parts. Each part is one-third of the whole bar.

1. First, take your object or shape (like a pizza or cake).
2. Then, divide it into three parts that are exactly the same size.
3. Finally, each part is one-third of the whole.

It’s important that the parts are equal. If one piece is bigger than the others, it’s not a third – it’s more or less than one-third.

Examples you can see

Let’s look at some examples to help you understand:

Example 1: A pizza

You have a pizza cut into three slices. If all slices are the same size, then each slice is one-third of the pizza.

Each slice is one-third of the pizza.

Example 2: A cake

Imagine you have a cake and want to share it with your two best friends. You cut it into three pieces, and all pieces are the same size.

• One piece = one-third of the cake
• Two pieces = two-thirds of the cake
• All three pieces = three-thirds = the whole cake

Example 3: A drawing

Draw a rectangle and divide it into three equal parts with lines. Each part is one-third of the rectangle.

Each part is one-third of the rectangle.

Try it as a mini adventure

Let’s go on a Thirds Treasure Hunt!

You are a treasure hunter, and you’ve found a secret map. The map shows a treasure chest that must be split into three equal parts. You need to find three equal pieces of a shape or object to unlock the chest.

1. First, find something to divide into thirds – maybe a sandwich, a piece of paper, or a chocolate bar.
2. Second, carefully cut or draw lines to make three equal parts.
3. Third, check that all parts are the same size. If they are, you’ve found the treasure!

Now, let’s pretend you are sharing this treasure with two friends. Each of you gets one-third. If you had 12 pieces, how many would each friend get? (Answer: 4 pieces each)

Common mistakes

• Mistake: Thinking that any three pieces make thirds.
  Why it happens: Children may not understand that the pieces must be equal.
  Fix: Always check that each part is the same size when making thirds.
• Mistake: Drawing lines that don’t make equal parts.
  Why it happens: Not measuring or comparing carefully.
  Fix: Use a ruler or fold paper to make sure parts are the same size.
• Mistake: Counting parts as thirds without checking if they are equal.
  Why it happens: Rushing or not paying attention.
  Fix: Slow down and compare each piece to make sure they are equal.

Parent and carer guide

Here’s how you can help your child understand thirds:

• Use everyday items: Share food like pizza or cake into three equal parts. Ask your child to tell you which part is one-third.
• Draw and cut: Draw shapes and ask your child to divide them into thirds. Then cut out the parts to check if they are equal.
• Ask questions: “Are these parts the same size?” or “How many thirds make a whole?”
• Be patient: It takes time to understand equal sharing. Let your child practice and make mistakes – that’s how they learn!
• Don’t worry: If your child gets confused, don’t panic. Use more examples and hands-on activities to build confidence.

Practice questions

1. Question: If a cake is cut into 3 equal pieces, what fraction is each piece?
   Answer: One-third (1/3)
2. Question: How many thirds make a whole?
   Answer: Three thirds
3. Question: If you have 12 cookies and want to share them equally among 3 friends, how many cookies does each friend get?
   Answer: 4 cookies each
4. Question: Draw a rectangle and divide it into three equal parts. Label one part as one-third.
   Answer: (Visual answer – not shown here)
5. Question: Is it possible to have thirds if the parts are not equal? Why or why not?
   Answer: No, because thirds must be equal parts of a whole.

FAQ

What does one-third mean?

One-third means one of three equal parts of something. For example, if you cut a pizza into three equal slices, one slice is one-third of the pizza.

Can you give me a real-life example of thirds?

Yes! If you have a chocolate bar and want to share it with two friends, you cut it into three equal pieces. Each piece is one-third of the bar.

How are thirds different from halves?

Halves split something into two equal parts, while thirds split something into three equal parts. So, halves are two parts, and thirds are three parts.

How can I teach my child thirds at home?

You can use food, drawings, or everyday objects. Share snacks into three equal parts, draw shapes divided into thirds, or use blocks to show how to split things into three equal groups.

What are some fun ways to learn about thirds?

Try cutting paper into thirds, sharing snacks with friends, or playing games where you split things into three equal parts. You can also use apps or online games that focus on fractions and equal sharing.