Video Transcript
How many pints are there in five customary cups?
Here’s what we know. We know that in every pint, there are two customary cups. We can think of it like this. If this is a representation of a pint, then each of these cubes would represent a cup. And in this example, we have five cups. And it takes two cups to make a pint. So here would be a picture representation of how many pints there are in five cups. One whole pint here plus another whole pint plus one out of two, so plus one-half of a pint. This picture shows us that in five customary cups, there would be two and one-half pints.
The thing is, we won’t always be able to draw a picture. What if that number, five, was 270. You wouldn’t want to draw that many cups and that many pints. So we need another way to solve this. If we’re moving from pints to cups, we multiply by two. In this problem, we’re moving from cups to pints. We’re going in the opposite direction. Do you have any idea about what kind of math operation could represent that? What would be the opposite of multiplying by two?
To move from cups to pints, we divide by two. If I take five and divide it by two, we can write it like this: five over two. That’s the same thing as saying five divided by two. And then we break up this improper fraction into two pieces, four divided by two plus one divided by two. Four divided by two equals two, and we don’t change the one-half.
Five cups equals two and one-half pints.