Comparing products without multiplying (fractions)
About this video
Lila brought 6 liters of water, Omar brought 4/3 as much and Zoe 2/3 as much. Without multiplying, the video reasons that multiplying 6 by a fraction greater than 1 gives more than 6 and by a fraction less than 1 gives less than 6. So from least to greatest the order is Zoe, Lila, Omar.
You'll be able to
- tell whether a fraction is greater than or less than 1.
- predict whether multiplying by a fraction makes a number bigger or smaller.
- order amounts like '4/3 as much' and '2/3 as much' without multiplying.
Key words
- as much as
- Comparing amounts: '2/3 as much as 6' means 2/3 x 6.
- fraction greater than 1
- A fraction whose top number is bigger than its bottom number, like 4/3.
- fraction less than 1
- A fraction whose top number is smaller than its bottom number, like 2/3.
Transcript
- [Tutor] We are told that Lila brought six liters of water to the picnic. Omar brought four thirds as much water as Lila, and Zoe brought two thirds as much water as Lila. Put Lila, Omar, and Zoe in order from the least to the greatest amount of water they brought.
Okay, pause this video and have a go at this before we do this together. Okay, so let's just think about this. Lila brought exactly six liters of water. Omar brought four thirds as much water. So four thirds, this is greater than one, so this four thirds as much water.
If I'm multiplying something larger than one times six, I'm gonna get something larger than six. So this is going to be greater than six. Four thirds is much water, it's going to be four thirds times six is one way to think about it, which is gonna be greater than six.
And then if we think about Zoe, Zoe brought two thirds as much water. Two thirds is less than one. So if I multiply two thirds times six, that's going to be less than six liters of water. So now we can put 'em in order. The person who brought less than six liters is Zoe, so Zoe is the least.
We wanna go from least to greatest. Then Lila is in between. Lila. And then the most, because it's more than six liters, four thirds times six, that's going to be Omar. And we're done.
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