# Video: Equal Parts

In this video, we will learn how to divide shapes into equal and unequal parts, count the parts, and work with the terms “part” and “whole.”

10:09

### Video Transcript

Equal Parts

In this video, we’re going to learn how to divide shapes into equal and unequal parts and to count these parts. We’re also going to be working with the terms “part” and “whole.”

These two birds are arguing over a cheese sandwich that they found lying around. They’re going to need to split it into two pieces. There we are: one, two, a piece for each bird. Is this fair? What do you think? Do you think both birds are going to be happy with the way that the sandwich has been divided? One of these birds isn’t gonna be happy at all. The two parts that the sandwich has been split into are not equal.

The word equal means the same. And because we’re talking about parts of shapes here, we use it to mean the same size. The whole cheese sandwich has been split into two parts. But as we’ve said, these parts are not the same size. They are not equal parts. They are unequal parts. For our birds to split this sandwich fairly, they need to share it so that each part is the same size. The pieces or the parts of the sandwich are now equal.

Now, we’re not going to think about sandwiches in this video. We’re going to think about 2D shapes like this rectangle and this circle. Let’s start with the rectangle at the moment. It’s a whole rectangle. Let’s split it into pieces. One, two, three. The rectangle has been divided into three parts.

But how could we describe those parts? Are they equal? Or are they unequal? There’s only one question we need to ask ourselves here. Are the parts in the shape the same size? If we look at the three parts that we’ve divided our rectangle in, we can see that they’re not the same size. This part in the middle, for example, is a lot wider than this part on the end. If you like chocolate and this was a chocolate bar and somebody gave you this piece, you’d say that’s unfair. My piece is smaller than the others. These parts are unequal.

Let’s look at the circle now. We’ve divided it into four parts. Let’s ask ourselves the same question again. Are the parts in the shape the same size? They’re not, are they? For example, this part here is a lot larger than this part here. If this was a giant cookie and you like giant cookies, you won’t be very happy if you have this part. It hasn’t been divided fairly. This is another example of a shape where the parts are unequal. Let’s make them equal. We’ll start with the whole shape again. And if we draw a line exactly down the middle, we’ve divided our shape into equal parts. And to give us four equal parts, we need to draw a line across the circle in the other direction, right in the middle.

This is a lot better. It’s a lot fairer. Nobody would be complaining if we divided a giant cookie this way. That parts in the shape are the same size. They are equal. Let’s try answering some questions now where we need to think about whether the shapes in the questions have been divided into equal or unequal parts.

Pick the group that this shape belongs to.

We’re given a picture of a rectangle, and our question asks us to pick the group that this shape belongs to. Underneath the picture, we can see the two groups that we’re talking about. One is labeled equal parts and the other is labeled unequal parts. The word both these groups have in common is the word “parts.” Both groups contain shapes that have been split into different pieces or parts. They both contain orange rectangles, and they both contain green circles. If we count the number of parts that each of the rectangles have been split in to, we can see that they’ve both been split into two parts.

But what’s the difference? Have they both been split in the same way? The parts in the first rectangle are the same size. They are equal parts. But if we look carefully at the rectangle in our second group, we can see that the parts are not the same size. They are unequal parts. Now, we’re beginning to understand what each group shows. The circle in this group has been divided into four parts and they’re all the same size. The circle in the second group has also been divided into four parts, but they’re not all the same size.

Let’s go back to look at our pink rectangle. Are the parts that this rectangle’s been split into the same size? It’s been split into three parts, hasn’t it? And when we look at them, they do look the same size. They are equal parts. The shape has been divided fairly into parts or pieces that are all the same size. It belongs in the group of shapes with equal parts.

Which picture shows equal parts?

We can see three pictures of three shapes. There’s a circle and two squares, but we can also see a line across each of the shapes. It’s a line that divides each shape into two pieces. But not all the shapes have been divided fairly. Our question asks us, which picture shows equal parts? This is really asking us, which picture shows parts that are the same size? Let’s start with our circle. If you wanted to split a circle into equal parts, where would you draw a line? Will you put it right down the middle, wouldn’t you, or across the middle? This line isn’t in the middle. This part at the bottom is a lot bigger than the part at the top. These are unequal parts.

Now, let’s look at the two parts that our blue square has been divided into. They look the same size, don’t they? If you’re not sure about this, turn your head slightly and look at it from an angle. It might help you to see that the two parts are the same size. These are equal parts. And if we just check our last shape, we can see that they’re not the same-size parts. For example, this part here is a little bit smaller than the top part. And so the only shape that’s been split or divided into equal parts is the blue square. The parts are the same size.

Which shape is divided into three equal parts?

We’re shown pictures of four shapes here. There are three rectangles and a circle. And each of the shapes has been divided or split up into parts. And we’re being asked to find the shape that’s been divided into three equal parts. We know that when parts or pieces of a shape are equal, they are the same size. Would you say that our first rectangle has been divided into equal parts? It hasn’t, has it? These two pieces are smaller than this piece here. They are different-sized pieces. So although this rectangle has been divided into three parts, they are three unequal parts.

Now, let’s look at this circle. This shape has been divided into three parts, too. Are they the same size? They’re not, are they? This part here is a lot larger than the other parts. This is another shape that’s been divided into three unequal parts. Now, let’s think about the top rectangle. What do you think about this one? Is each part the same size? They certainly look that way, don’t they? Perhaps, this is our answer.

But if we look at our bottom rectangle, it looks like this has been divided into equal parts, too. We can’t have two correct answers. The question only asked us for one shape. If we look carefully at the question, we can see we’re looking for a shape that’s been divided into three equal parts. The top rectangle has been divided into four equal parts. So although they are the same size, it’s not what we’re looking for. The correct answer is the shape that’s been divided into three pieces that are all the same size. The shape that has three equal parts is the orange rectangle.

What have we learned in this video? We’ve learned how to divide shapes into equal and unequal parts and to count those parts. We’ve also worked with the terms “part” and “whole.”