Parts and Wholes
In this video, we’re going to learn
how to partition or split numbers up to 10 into two or more parts. Also, we’re going to learn how to
use the words part and whole correctly.
Let’s start by thinking about this
apple. We can see that it’s a complete
apple; nothing’s missing from it. We can use the word whole to
describe this apple. And we’re not talking about a hole
in the ground. This word has got a “w” at the
start of it. We use the word whole when we’re
talking about all of something, when an object or a number is complete. Our apple’s complete, and so we can
say it’s a whole apple.
Now, let’s imagine that we take a
knife and we cut our apple. By cutting our apple, we’ve split
it. Another word for this is
“partition.” We’ve partitioned the apple. And instead of having one whole
apple, we now have two parts of an apple. We can use the word part to
describe some of something.
Here’s a slice of cream cake. Is this a whole or a part? We know that a slice of a cake is
part of a cake. The whole cake has been
partitioned. Here’s the rest of the cake. We can say that this is another
part of the cake. One part is bigger than the other,
but they’re both parts. They’re both some of a cake, not
all of a cake. But what if we put our two parts
together? This is a bit like what we do when
we add numbers, isn’t it? By adding the two parts together,
we can make a whole cake.
We can show parts and wholes using
a model like this. In the first circle, we can show
the whole amount or write the whole number. And then, these circles show the
parts that the whole has been split into. And we could do this with everyday
objects that we’ve partitioned, numbers that we’ve modeled.
This part-whole diagram shows that
four counters can be split into a group of one counter and a group of three
counters. And you know we could show exactly
the same number fact by replacing our counters for numbers. Four is equal to one and three. You see how these part-whole models
work? We can start with the parts, then
put them together. And this gives us our whole
amount. Let’s try using part-whole models
like this as we answer some questions to do with parts and wholes.
Emma has five blocks. She put them into two groups and
found that five is two and three. And we can see a picture there of
Emma saying that five is two and three. How else can she make five? Hint: make two groups with five
objects. Five is five and one, five is two
and two, or five is one and four.
This question is all about parts
and wholes. To begin with, we’re told that Emma
has five blocks. This is the whole amount, the total
amount that Emma has. But we’re then told that Emma puts
her five blocks into two groups. She splits them up or partitions
them. And so, instead of having one whole
amount of blocks, she now has two parts. And we can see how she does this in
the picture. We call this sort of a picture a
part-whole diagram. Let’s think about how Emma made her
So, to begin with, Emma had five
blocks. This is the whole amount. And these are the five blocks that
we can see in the top circle. And then, what she did was to split
her five blocks into two groups. What we’ll do is we’ll move our
five blocks into two groups so we can see how she found her answer.
In the first group, she put one,
two blocks. And in the second group, she was
left with one, two, three blocks. And that’s how she knows that five
is two and three. Now, the question asked us, how
else can she make five? And to help us answer the question,
we’re given a hint. We’re told to make two groups with
five objects. Let’s go through each of our three
possible answers to find out which is correct.
Our first possible answer says five
is five and one. Let’s use our part-whole diagram to
see if we can split five into five and one. Our first part needs to be made up
of five blocks. One, two, three, four, five. We’ve used up all of the
blocks. There are five blocks in one part
and zero blocks in the other part. So, we can see that five isn’t five
and one. It’s actually five and zero. Let’s put a little cross by this
statement so that we remember it’s not right.
Our second statement says five is
two and two. Let’s partition our whole amount
into two and two. One, two. One, two. We’ve still got one more block that
we need to split up. Let’s add it to our second
part. We have two in the first part and
three in the second part. We can see that five isn’t two and
two. It’s two and three. Let’s put a cross by that.
We only have one more possible
answer. Can Emma split five blocks into one
and four? Let’s see. One, now, how much is in our second
group? One, two, three, four. We had five objects. And we’ve made two groups out of
them. And so, another way that Emma can
make five is by splitting or partitioning her blocks into one and four. Five is one and four.
There are seven cubes altogether
and four of them are red. What number is missing from the
number bond? Hint: Use the blue cubes to help
The first thing we’re told in this
question is that there are seven cubes altogether. You know this word “altogether”
means we’re talking about the whole amount. And if we look at the picture
underneath, we can see a line of seven cubes. One, two, three, four, five, six,
seven. And if we look at the part-whole
diagram underneath, we can see the whole amount. Here’s the number seven in our
Now, this whole amount is made up
of two parts, a red part and a blue part. We’re told that four of the seven
cubes are red. And again, we can see the four
cubes in the picture. And also, the number four is
labeled on our part-whole diagram. The question asked us, what number
is missing from the number bond? Now, this phrase “number bond” is
just another way to describe our part-whole diagram. A number bond is just a way of
showing how different numbers go together to make a total.
And our number bond shows that four
and something make seven. We need to find out what that
something is. We know that the number four
represents the red cubes. And that’s why our hint asked us to
use the blue cubes to help us. We need to count the blue cubes to
see what goes together with four to make seven. Let’s count these blue cubes. One, two, there are three blue
cubes. So, we know that four and three
make seven. The whole amount of seven can be
split into two parts, four and three. The number that’s missing from the
number bond is three. Seven can be split into four and
Ethan has four counters. He wants to find ways to make
four. You see a picture of him there
asking, how many ways can I make four? What number is missing? Hint: make two groups with four
counters. And Ethan is asking, four is one
and what? Find another way to make four. What number is missing? Four is two and what?
The first thing we’re told in this
problem is that Ethan has four counters. And he wants to find ways to make
four. And if we look at the picture, we
can see that Ethan has a part-whole diagram. This is a way of showing number
bonds, numbers that go together to make a total. And in this case, it’s numbers that
go together to make a total of four.
Our first question asked us what
number is missing. Missing from where? Well, missing from this second
part-whole diagram and from Ethan’s statement where he says, four is one and
what? In other words, how can we make
four? We can put together one counter and
how many more counters? We’re given a hint to help us find
the missing number. And that’s to make two groups with
four counters. So, let’s do that.
Here are four counters. This is the whole amount. Now, let’s split them into two
parts. We know that the first part must be
one because Ethan says four is one and something. So, let’s color our one counter a
different color to the rest. There we go. We’ve made two groups out of four
counters. There’s one counter in our first
group. And there are one, two, three
counters in our second group. We can use this to complete our
part-whole diagram. Four is the same as one and
three. So, the number that’s missing in
Ethan’s sentence is the number three.
The next part of our problem asked
us to find another way to make four. What number is missing? Four is two and what? Let’s start with four counters
again. Here are our four counters that
we’re going to start with. And we’re told that four is two and
something. So, let’s color our first group,
our first part, which is worth two. So, what goes together with two to
make four? One, two, we can partition or split
four counters into a group of two and another group of two. Four is two and two. Our missing number is two.
So, what have we learned in this
video? Firstly, we’ve learned how to use
the words part and whole correctly. We’ve also learned how to partition
or split numbers up to 10 into two or more parts.