Video Transcript
There are four balloons, and
all of them have popped. How many are left? Write the equation that
explains this situation. Four take away zero equals
four, five take away four equals one, four take away four equals zero, or five
take away five equals zero.
The first piece of information
we’re told in this problem is that there are four balloons, although perhaps we
should say there were four balloons because we’re then told that all of them
have popped. And we can see this in the
picture. Now, there’s a very important
word in this sentence and that’s the word “all.” We’re told, all of them have
popped. What does the word “all”
mean? Well, it means every single one
of them. And in this question, the word
“all” represents the number four. We had four balloons and all of
them have popped. So that means four of them have
popped. And of course, we can see if we
count the remains of the balloons in the picture that four of them have
popped.
And we’re asked how many are
left. Well, perhaps we know what the
answer is already. But let’s model the question
using counters just to be sure. These four counters can
represent our four balloons. Now, let’s take away counters
to represent the balloons popping. Remember, we need to show that
all of them have popped, so we need to take away one, two, three, four. Four take away four leaves us
with nothing. And so if all of the balloons
popped, we’re left with zero.
The next part of the problem
asks us to write the equation or the number sentence that explains the
situation. Which of these number sentences
shows us that there will be zero balloons left if we pop all four of them? Well, if there is zero balloons
left, then we’re looking for an answer that is zero. So that means we can ignore the
first and the second number sentences here. Both of our two remaining
number sentences have an answer of zero. But which one is correct? Four subtract four equals zero
or five subtract five equals zero. There were four balloons and
all four of them popped. So the equation that explains
this is four take away four equals zero. When we subtract all of a
number from itself, we’re left with nothing or zero.
