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.”
