Video Transcript
If I have four marbles and you give
me zero marbles, then I still have four marbles. So, four plus zero equals four. If I have zero marbles and you give
me four marbles, how many marbles do I have? Write an addition sentence to show
the answer.
This problem is a little bit like a
story. And we could use maths equipment to
help us find out what the answer is. Let’s read it through again from
the very start. Firstly, we’re told that we begin
with four marbles. It says, if I have four
marbles. So, let’s start by taking four
counters. These can represent our four
marbles.
In the problem, we’re told that you
do something to my four marbles. You give me another zero
marbles. We know that zero is the same as
nothing. That’s why the hand at the top of
the picture hasn’t got anything in it. And that’s also why if we’re using
counters to show this problem, we don’t need any. Zero means no more.
The sentence goes on to tell us
that if you give me zero marbles, I will still have four marbles. And this story is also represented
by an addition sentence or an equation. Four plus zero equals four. We can also see this by looking at
the part–whole model we’ve made using counters. Four counters plus no more counters
makes a total of four counters. When we add zero to a number, it
stays the same.
The next part of our story problem
ends in a question. If I have zero marbles and you give
me four marbles, how many marbles do I have? We can see this being shown in the
picture, too. Here’s my hand. It has zero marbles in it. And here’s your hand giving me four
marbles. To find the answer, we need to add
together zero and four. We could even write these numbers
as part of our addition sentence straightaway. We know that what we need to do is
to add zero, that’s the number that I have to begin with, and four, that’s the
number that you give me. Let’s use counters again to model
what we’re being asked.
I start off with zero marbles. So, we don’t need to draw any
counters there. Then, you give me four marbles. Now, we need to combine both sets
of counters to show what the total is. The total is four. The number of marbles that I have
now is four. If we add a number to zero, the
answer’s going to be the same as the number we added. The addition sentence or equation
that shows the answer to this problem is zero plus four equals four.
