Video Transcript
A boy has seven boxes of fish and a
girl has one box of fish. Each box has 10 fish. How many fish do they have
together?
When we look at a word problem like
this, we can’t see a symbol to tell us what to do. You know there’s something else we
can’t see, too. We can’t see how many steps we need
to do to solve the problem. Sometimes, we need to do more than
one thing. First of all, let’s look at what
this problem is asking us to find out. Well, we’re told about a boy and a
girl who both have boxes of fish. And we need to find out how many
fish they have together. In other words, what’s the
total?
Now, what have we been told in the
question that’s going to help us to solve the problem? Well, we know that the boy has
seven boxes of fish and the girl has one box of fish. And we’re also told how many fish
there are in each box. And that’s 10. Let’s model the problem to work out
what it is we need to do to solve it. Here are the boy’s seven boxes of
fish and let’s include the girl’s box of fish as well. So, the number of boxes of fish
that they have is seven plus another one. But we’re also told that each box
contains 10 fish. So, we’re going to need to find a
few lots of 10, aren’t we?
This is going to involve
multiplication. So, we can see by looking at this
model what we need to do to find the total amount. There are going to be two steps to
our problem. First of all, we need to add
together seven and one more, which, of course, is eight. So, we can start by saying that
there are eight boxes of fish altogether. And because there are 10 fish in
each box, we need to find the answer to eight lots of 10, eight multiplied by
10. Now, of course, we know this is
80.
Although we had to multiply in this
problem, we also had to add to begin with. It was a two-step problem. There were two things we needed to
do. We found the total number of boxes
by adding seven and another one. And then, we multiplied this answer
by 10 to find out the total number of fish. Together, the children have 80
fish.
