WEBVTT
00:00:01.440 --> 00:00:05.680
How many pints are there in five customary cups?
00:00:09.020 --> 00:00:10.020
Here’s what we know.
00:00:10.540 --> 00:00:15.540
We know that in every pint, there are two customary cups.
00:00:18.150 --> 00:00:19.720
We can think of it like this.
00:00:19.950 --> 00:00:28.790
If this is a representation of a pint, then each of these cubes would represent a cup.
00:00:30.990 --> 00:00:35.340
And in this example, we have five cups.
00:00:37.750 --> 00:00:40.420
And it takes two cups to make a pint.
00:00:40.980 --> 00:00:48.660
So here would be a picture representation of how many pints there are in five cups.
00:00:49.880 --> 00:01:00.330
One whole pint here plus another whole pint plus one out of two, so plus one-half of a pint.
00:01:01.920 --> 00:01:08.860
This picture shows us that in five customary cups, there would be two and one-half pints.
00:01:10.760 --> 00:01:14.370
The thing is, we won’t always be able to draw a picture.
00:01:14.680 --> 00:01:18.060
What if that number, five, was 270.
00:01:18.550 --> 00:01:22.230
You wouldn’t want to draw that many cups and that many pints.
00:01:22.490 --> 00:01:24.560
So we need another way to solve this.
00:01:26.620 --> 00:01:32.700
If we’re moving from pints to cups, we multiply by two.
00:01:33.380 --> 00:01:37.360
In this problem, we’re moving from cups to pints.
00:01:38.150 --> 00:01:40.230
We’re going in the opposite direction.
00:01:40.680 --> 00:01:45.400
Do you have any idea about what kind of math operation could represent that?
00:01:46.860 --> 00:01:50.080
What would be the opposite of multiplying by two?
00:01:51.720 --> 00:01:57.170
To move from cups to pints, we divide by two.
00:01:59.370 --> 00:02:07.320
If I take five and divide it by two, we can write it like this: five over two.
00:02:07.320 --> 00:02:10.090
That’s the same thing as saying five divided by two.
00:02:12.210 --> 00:02:21.050
And then we break up this improper fraction into two pieces, four divided by two plus one divided by two.
00:02:22.850 --> 00:02:30.100
Four divided by two equals two, and we don’t change the one-half.
00:02:30.530 --> 00:02:34.510
Five cups equals two and one-half pints.