Video Transcript
There are five carrots. A rabbit eats three of them. Which of the following gives the
number of carrots left? Three subtract two equals five,
five subtract two equals three, five equals three subtract two, five subtract three
equals two, or three equals five subtract two. Which of the following is another
subtraction equation for the number of carrots left? Three equals five subtract two, two
equals five subtract three, five subtract two equals two, or five subtract two
equals three.
We’re given lots of subtraction
facts to choose from in this question. And did you notice they all sound
very similar. That’s because the numbers five,
three, and two keep cropping up, don’t they? It could be very easy to get
confused with this question, so we’re going to have to read it really carefully. To begin with, we’re told that
there are five carrots. Can you see them in the
picture? One, two, three, four, five. But these five carrots aren’t
around for long because we’re told that a rabbit eats three of them. And we can see these in the picture
too, can’t we? These are the carrots that have
been crossed out, one, two, three. So, there were five carrots to
begin with and a rabbit has eaten three of them.
Our first question asks us, which
of the following gives the number of carrots left? Well, first of all, can you see how
many carrots are left, one, two. Now, we’re given the five different
subtraction facts to choose from, but only one of them is a way of showing what’s
happened to these carrots. Let’s try and write down what’s
happened as a subtraction fact and then look for a fact that matches what we’ve
written.
We were told we had five carrots to
start with, so let’s write down the number five. And we also know that a rabbit eats
three of them. This is the same as taking away
three of them, isn’t it? So, we’re going to write the
subtraction symbol and then the number three, five take away three. Now, as we’ve just said, we’ve
counted how many carrots are left, and there are two. So, the subtraction that shows us
the number of carrots left is five take away three equals two. Now can you see this subtraction
fact in the ones that we’re given? Yes, we can. Five take away three equals
two.
But there’s another part to this
question. We’re asked which of the following
is another subtraction equation for the number of carrots left. And we’re asked this question
because although we can write five subtract three equals two, there’s another
subtraction fact that we can write. This time, let’s go through each
subtraction really carefully and try to understand what it’s telling us.
Firstly, three equals five take
away two. Now, this is interesting because
this subtraction starts with the answer and then we have the subtraction. But what it means is three is what
we have left over if we start with five and we take away two. So, we could model this using
counters. Here are five counters. And it is correct; three is what’s
left over if we start with five and take away two. But it’s not what’s happened to our
carrots, is it? The rabbit ate or took away three
of them, not two. So, the subtraction we’re looking
for is not this one.
The next subtraction says two
equals five take away three. This is another calculation that
starts with the answer. But if we think about what it
means, it’s telling us that two is what’s left if we start with five and take away
three. And if we model this with counters,
we can see that this is exactly what happens to our carrots. Two carrots are what’s left over if
we start with five and take away three. And if we write the subtraction
underneath the one we’ve already got at the top, we can see that it’s almost exactly
the same. The parts of it are just switched
around a little bit. Five take away three equals
two. Two equals five take away
three.
If there are five carrots and a
rabbit eats three of them, we can find out the number of carrots left by working out
five take away three equals two. And another way of saying exactly
the same thing is two equals five take away three.
