Video Transcript
Word Problems: Putting Objects
Together
In this video, we’ll learn how to
solve problems with numbers up to 10. We’re going to find a total when
one or more objects are added to a group. A word problem is exactly how it
sounds. It’s a maths problem that’s been
written in words. We’re going to have a go at
answering some word problems. But before we do, let’s remind
ourselves of four things we can do to help.
Number one, we need to read the
problem carefully. Sometimes when a problem’s being
written in words, it’s easy to make a mistake or to miss something out. Reading the problem carefully means
reading it slowly and perhaps reading it more than once. This way, we can make sure we
understand what it says. The second thing we can do as we
read our problem carefully is to look out for hints. Often, we can find words that’ve
been used in the problem that will give us a clue as to how to work out the
answer. For example, we might see the
words, what is the total? And this might give us a clue that
we need to add to find the answer.
If we can, it’s always useful to
act out or model the problem. This is the third thing we can do
to help ourselves. For example, we could use maths
equipment to help us understand what the question is asking.
The last thing that we can do is to
turn our word problem into a number sentence that we can solve. And once we’ve written our number
sentence, we can then find the answer and solve the problem. Do you think you can use these four
steps to solve some problems? Let’s have a go.
Daniel read this addition
story. There are three strawberry
candies and three lemon candies. Pick the model that matches the
story. How many candies are there? Three plus three equals
what?
Here, we’ve been given a
problem that’s written in words. It’s a word problem. Let’s begin by reading it
really carefully to find out what we have to do. To start with, we’re told that
Daniel read this addition story, and then we’re given the story. There are three strawberry
candies and three lemon candies. Perhaps he’s looked in his bag
of sweets and he can see what’s in there. It might be a good idea to
underline these two amounts because they could be important — three strawberry
candies, three lemon candies.
The next sentence of our word
problem asks us to pick the model that matches the story. And underneath, we can see two
part–whole models that have been drawn for us, but only one of them matches the
story. Which one? In the first model, we can
count one, two, three, four, five, six candies in the first circle. And there aren’t any candies in
the second circle. This part–whole model would
show us a problem that involved adding six and zero together.
In our second model, we can see
the first circle contains one, two, three candies. And our second circle or second
part contains one, two, another three candies. In other words, our part–whole
model shows three plus three, the total of three and three. Now, which of these models
represents three strawberry candies and three lemon candies? It’s the model that shows three
plus three. And in the final part of our
problem, we need to find the total. How many candies are there? It asks. Three plus three equals
what? Our word problem has been
written as a number sentence.
Let’s model the number sentence
using counters to help us find the answer. We could even use different
colored counters to help us remember that these are strawberry and lemon
flavored. So what is the total of three
and another three? Well, we already know we have
one group of three, so let’s count on another three from that. Three, four, five, six. We’ve used addition to put two
groups of objects together. The correct model is the one
that shows three candies and another three candies. And we’ve found the number of
candies altogether by adding three and three together. And the answer is six.
David has four black cats and
two white cats. How many cats does he have in
total? Find the matching number
sentence. Four plus two equals five,
three plus two equals five, four plus two equals six, or four plus three equals
seven.
Let’s start by reading through
our word problem again carefully so that we understand what it’s asking us. To begin with, we’re told that
David has four black cats and two white cats. Let’s underline these numbers;
they could be useful. And underneath, we can see a
picture of David’s four black cats and two white cats. And then we’re asked, how many
cats does he have in total? There’s a clue in this question
which tells us what we need to do to find the answer. When we find the total of
something, we need to add to find the answer. So in this problem, we need to
add together four and two.
Let’s model the problem. We could use black and white
cubes, couldn’t we? Four black cubes representing
the four black cats and then two white cubes representing our two white
cats. So to find the number of cats
that David has in total, we need to add on another two to four. This means we can just count on
from four. We know we have four black
cubes, so we then have five, six cubes altogether. David has a total of six
cats. Although our problem was in
words, we can represent it using a number sentence. And we need to find the
matching number sentence. Do you remember what we did to
find the answer? We added together four and
two.
Out of the different additions,
we can see that only two of them show four plus two. But which one’s correct? Four plus two equals five or
four plus two equals six. We’ve already found the answer,
so we know that the matching number sentence is four plus two equals six. David has six cats in total,
and the matching number sentence is four plus two equals six.
Ethan bought five blue pens and
two green pens. How many pens does he have in
total? Find the matching number
sentence. Three plus five equals eight,
five plus two equals seven, five plus two equals six, or five plus four equals
nine.
Let’s take our time and read
through this word problem again. Ethan bought five blue pens and
two green pens. Let’s underline these two
amounts; they’re going to come in useful later on. The question continues, how
many pens does he have in total? And we know, of course, that
that word “total” means that we’re going to have to add to find the answer. We need to find how many pens
Ethan has altogether. This is an addition word
problem. We’re putting two groups of
objects together. Let’s model the problem. We could use a part–whole model
using counters. Five blue counters to represent
Ethan’s five blue pens. And we can use two green
counters to represent his two green pens.
And the question is asking us,
how many counters are we going to need to put in this top circle of our
part–whole model? In other words, how many pens
did Ethan have in total? Let’s move our counters one by
one into that top circle. And we’ll count them as we
do. Altogether, Ethan is going to
have one, two, three, four, five, six, seven pens. We solved the word problem by
modeling it using counters. Five blue pens plus another two
green pens makes seven pens in total. We can also show our word
problem as a number sentence.
And in the second part of the
question, we’re asked to find the matching number sentence. Which number sentence shows us
that five blue pens and two green pens makes a total of seven pens? Well, it’s this one here, isn’t
it? Ethan has seven pens in
total. And the matching number
sentence is five plus two equals seven.
There are three black sheep and
five white sheep in a field. How many sheep are in the
field?
Let’s start by reading through
our word problem again. To begin with, we’re told that
there are three black sheep and five white sheep in a field. And the question then asks us,
how many sheep are in the field? We know that there are three
black sheep and five white sheep, but the question’s asking us, how many sheep
there are altogether? How could we find the
answer? What do we need to do? Well, we could start by just
doing a quick sketch so that we understand what the question is asking us. Here are three black sheep. You don’t have to be able to
draw a sheep to be able to answer the question. These look just like clouds
with legs, don’t they? But they’ll do.
Three black sheep and five
white sheep. To find out the total number of
sheep in the field, we need to add three and five together. Three plus five equals
what? Let’s use a number track to
help us find the answer. We could start with the number
three, this represents our three black sheep, and then count on another
five. One, two, three, four,
five. We’ve ended on the number
eight. We’ve used addition to add two
groups of sheep together. Three plus five equals
eight.
What have we learned in this
video? We’ve learned how to solve word
problems with numbers up to 10. And we’ve done this by finding the
total, when one or more objects are added to a group.
