Addition bar models
Draw bars to represent parts and wholes in word problems.
Quick answer
Addition bar models are a way to draw bars to show parts and wholes in word problems. They help you see what numbers you need to add together and make solving addition problems easier.
Learning outcome
By the end of this page, you will be able to use bar models to show addition problems and solve them by adding parts together to find the whole.
Success signs:
- You can draw a bar model to show two or more parts that make a whole
- You can use a bar model to solve a word problem with addition
- You can explain how bar models help you understand addition
- You can create your own bar model for a simple addition problem
Why this matters
Bar models help you understand addition problems without needing to read a lot of words. They are used in school to help children see what is happening in a problem. You can use bar models for problems like "I have 5 apples and my friend gives me 3 more. How many apples do I have altogether?" The bar model helps you see that you need to add 5 and 3.
Bar models are also useful in real life. For example, when you are planning a party and need to know how many people will come, or when you are cooking and need to add ingredients together, bar models can help you think through the maths.
How it works
Bar models are simple drawings that show how numbers relate to each other. Here's how to use them for addition:
- Read the problem carefully to understand what is happening
- Draw a long bar to represent the whole
- Divide the bar into parts that match the numbers in the problem
- Add the parts together to find the whole
- Write the answer in a sentence
For example, if the problem says "I have 4 stickers and I get 6 more", you draw two parts: one part for 4 stickers and one part for 6 stickers. Then you add them together to get 10 stickers.
Examples you can see
Let's look at a few examples of how to use bar models for addition:
Example 1: Simple addition
Problem: Sarah has 3 toy cars. Her brother gives her 5 more toy cars. How many toy cars does Sarah have now?
Bar model:
| Part 1 | Part 2 | Whole |
|---|---|---|
| 3 | 5 | ? |
Steps:
- Draw a long bar for the whole
- Split it into two parts: one part for 3 and one part for 5
- Add 3 + 5 = 8
- Write the answer: Sarah has 8 toy cars
Example 2: Three parts
Problem: Tom has 2 blue marbles, 3 red marbles, and 4 green marbles. How many marbles does Tom have in total?
Bar model:
| Blue | Red | Green | Whole |
|---|---|---|---|
| 2 | 3 | 4 | ? |
Steps:
- Draw a long bar for the whole
- Split it into three parts: 2, 3, and 4
- Add 2 + 3 + 4 = 9
- Write the answer: Tom has 9 marbles
Example 3: Word problem with a missing part
Problem: There are 12 children in the class. 7 children are boys. How many children are girls?
Bar model:
| Boys | Girls | Whole |
|---|---|---|
| 7 | ? | 12 |
Steps:
- Draw a long bar for the whole (12 children)
- One part is 7 boys
- Find how many girls there are by subtracting: 12 - 7 = 5
- Write the answer: There are 5 girls in the class
Try it as a mini adventure
Adventure: The Treasure Hunt
You are going on a treasure hunt with your friends. You find a map that says:
- Start at the big oak tree
- Walk 3 steps north
- Then walk 5 steps east
- Then walk 2 steps south
- Find the treasure!
Bar model challenge:
Draw a bar model to show how many steps you walked in total.
Steps:
- Draw a long bar to represent all your steps
- Split it into three parts: 3 steps, 5 steps, and 2 steps
- Add them together: 3 + 5 + 2 = ?
- Count your steps to check: 3 + 5 + 2 = 10
How many steps did you walk in total?
Answer: You walked 10 steps in total.
Common mistakes
- Mistake: Forgetting to add the parts together to find the whole
Why it happens: Children may draw the bars but forget to do the addition.
Fix: Always ask "What do I need to do with the parts?" and remember to add them together. - Mistake: Drawing the bars too small or too large
Why it happens: It's easy to make mistakes when drawing without a ruler or guide.
Fix: Use a ruler or draw the bars with even lines. The size doesn't matter, but they should be clearly separate. - Mistake: Not reading the problem carefully
Why it happens: Children may rush or not understand what the question is asking.
Fix: Read the problem twice and underline key numbers and words. - Mistake: Mixing up which part is the whole and which are the parts
Why it happens: When there are many numbers, it can be confusing.
Fix: Label each part clearly. The whole is what you are trying to find.
Parent and carer guide
Helping your child with addition bar models is easy and fun! Here are 5 simple ways to support them:
- Ask questions: Ask your child to explain what the bar model shows. For example, "What do these two bars represent?"
- Draw together: Sit down and draw bar models with your child. This helps them see how you think about the problem.
- Use real-life examples: Use things you do together, like counting snacks or adding up toys to make bar models.
- Be patient: Bar models take time to understand. Let your child take their time and make mistakes.
- Encourage: Praise your child when they get it right. Even if they make a mistake, tell them they are learning!
Remember, bar models are just a tool to help with addition. They are not the only way to solve problems. If your child finds another way that works, that's great too!
Practice questions
- Problem: Emma has 4 pencils. She buys 5 more pencils. How many pencils does Emma have now?
Answer: 4 + 5 = 9 pencils - Problem: There are 6 birds on a tree. 3 more birds fly to the tree. How many birds are on the tree now?
Answer: 6 + 3 = 9 birds - Problem: I have 2 red balloons and 7 blue balloons. How many balloons do I have in total?
Answer: 2 + 7 = 9 balloons - Problem: There are 8 children playing in the park. 4 more children join them. How many children are playing now?
Answer: 8 + 4 = 12 children - Problem: Tom has 3 toy cars. His sister gives him 6 more toy cars. How many toy cars does Tom have now?
Answer: 3 + 6 = 9 toy cars
FAQ
What is a bar model?
A bar model is a drawing that shows how numbers relate to each other. It helps you see what you need to add together.
When do I use bar models?
You use bar models when you have addition problems and want to see the parts and the whole clearly. They are especially helpful for word problems.
Do I have to use bar models?
No, bar models are just one way to solve addition problems. You can use other methods like counting or using your fingers.
Can I use bar models for subtraction?
Yes! Bar models can also be used for subtraction problems. You draw a bar for the whole, one part for what you have, and then find the missing part.
How can I practice bar models at home?
You can practice by making up simple word problems and drawing bar models for them. Use toys, snacks, or anything you have around the house to make it fun!