﻿Hi everyone, I'm Miss Mitchell and today we're going to be representing information in a bar model. In today's lesson, we'll be solving addition worth problems, solving subtraction word problems, then I'd like you to have a go at the worksheet and then a quiz. For today's lesson, you will need a pencil and some paper, pause this video now to get this, if you have not got it already. Here's a word problem. John picks apples from his garden, he picked three red apples and two green apples. How many apples did he pick all together? How could I represent this word problem in a part whole model? What's the values of my parts. The value of one part is three because John has three red apples, and the other part is two, because he had two green apples. The whole is the unknown. This means we don't know what the whole is and that is what we have to find out. I can write this as an equation. The equation is three plus two is equal to the unknown. Here you can see how we get the answer to this equation because the whole is made up of three red apples and two green apples. Altogether that are five apples. As three plus two is equal to five. We can represent the mass in the word problem, using another representation, a bar model. Just like in the part whole model, the value of one part is three, and the other part is two. I know by looking at this bar model, that three plus two is equal to five. So the answer is five. Let's try one together. John picked apples from his garden. He picked three red apples and four green apples. How many apples did he pick all together? What are the values of my parts and what is the unknown value? Pause the video and have a think. The value of one part is three, and the other part is four. The whole is the unknown value. Can you write this as an equation. Three plus four is equal to the unknown. Here again you can see the bar model. One part is three and the other part is four. And the whole is the unknown. I know now by looking at my bar model, that three plus four is equal to seven. So the answer is seven. Let's try a new one. John picked 12 apples from under one tree and six apples from another tree. How many apples did John pick all together? Can you have a go at this one by yourself. Pause the video and have a go. And here is the bar model. The value of one part is 12, and the other part is six. I know by looking at this bar bar model that 12 plus six is equal to 18. So the answer is 18. A great job. Now this word problem is a little bit different. Let's see if you can work out why. John brings in five apples in a basket and places two on the chopping board. How many are left in the basket? How can I represent this work problem in a part whole model? What are the values of my parts? The value of my hole is five because there are five apples, one, two, three, four, five. One part is two, because he places two on a chopping board. As you can see, this is taken from the whole. The other part is the unknown value. And this is what is left in the basket. This means we don't know what the part is and that's what we have to find out. Could you work up why this question is a little different? Its because we are subtracting, I can write this as an equation. The equation is five take away two is equal to the unknown. We can represent the subtraction word problem using a bar model too. Just like in the part whole model, the value of the whole is five. And the part is two. I know by looking at this bar model, that five take away two is equal to three. So the answer is three. Let's try another one together. John and Anne an apple pie. They chop six apples. Anne chops four of them. How many are left for John to chop? What is known to us and what is the unknown value? The value of my whole is six, and one part is four. This four is taken from the whole and that's why it's subtraction. The other part is the unknown value. Can you mark this as an equation? The equation is six subtract four is equal to the unknown. Can you represent the maths in the word problem, using a bar model. pause the video now and have a go. Here's what your bar model should look like. The whole is six and one part is four. So your equation is six take away four, which is equal to two. Can you try this one by yourself. When John brought his 18 apples into the kitchen, he saw that seven of them were bruised. How many apples were not bruised? Pause the video, draw your bar model and write your equation. Here's what your bar model should look like. The whole is 18, and one part is seven. The other part is the unknown. Therefore, your equation is 18 subtract seven is equal to the unknown, and I know the 18 takeaway seven is equal to 11. Have a go at answering these word problems. First, you need to read the question and work at what operation to use. Whether it's addition or subtraction. I like to underline any key words or numbers in the equation, then draw your bar models and work out the answer. Pause the video now and then press play when you're ready for the answers. And here are the answers. That's the end of learning today. You've done a great job and I hope you're proud of yourself. If you would like to share your work with Oak National, then please ask your parent or carer to share your work on Twitter tagging @OakNational and #learnwithOak. You've done so much learning. I now want to see what you have learned, so please make sure when the video has finished, you go on the next slide and you complete the quiz.

You’ve done so much learning. Try your best and complete the quiz. Draw bar-models to answer these questions.

Jack picked 8 apples from under one tree and 2 apples from under another tree. How many apples are there altogether?

Jack brought 15 apples in a basket into his kitchen. He placed 4 of the apples on a chopping board. How many were left in the basket?

Joe picked lots of apples. 4 of his apples were bruised and 5 were not bruised. How many apples does he have altogether?

When Muhammad got back into his kitchen with 17 apples, he realised 5 of them were bruised. How many were not bruised?

Ava placed 10 of her apples on the chopping board and Zain placed 7. How many apples are on the chopping board altogether?

Representing information as a bar model

In this lesson, we will read word problems and represent them as bar models.

Maths

Y2 Maths

Key Stage 1

Year 2

Representing information as a bar model (Part 1)

Addition and subtraction word problems

Number

THEME

UNIT

Representing information as a bar model (Part 2)

Creating and labelling bar models

Creating a bar model

Representing two step word problems using bar models (Part 1)

Representing two step word problems using bar models (Part 2)

Representing comparative word problems using bar models (Part 1)

Representing comparative word problems using bar models (Part 2)

Identifying suitable bar models to represent problems

Applying knowledge of bar models to answer word problems

21 children in the playground. 48 children arrive. Then 16 children leave. How many children are there now?

There were 19 children at lunch. 40 more children come to lunch. Then, 25 people left the lunch hall. How many children were left at lunch?

There were 38 bananas at the fruit stall. 11 of them were green. How many were yellow?

There were 64 apples at the fruit stall. 24 were red and the rest were green. How many apples were green?

Levi has 16 crayons. Ben has 4 fewer. How many crayons does Ben have?

Sam has 16 comics. Jade has 13 comics. How many more comics does Sam have?

Class 5J have 24 stickers. The boys get 11 more stickers and the girls get 14 more stickers. How many stickers do Class 5J have now?

The fruit stall has 68 apples. David takes 15 apples. Timmy takes 2 apples. How many apples are there now?

Lesson overview:Representing information as a bar model (Part 1)

Core Content

Addition and subtraction word problems: