Modeling fraction expressions with tape diagrams: pasta salad
About this video
A pasta salad recipe needs 3 cups of vegetables per batch, and Asha has 8 cups. Using a tape diagram split into 8 cups, the video marks off two full batches of 3 cups and sees 2 cups left over, which is 2/3 of a batch, so Asha can make 2 2/3 batches.
You'll be able to
- use a tape diagram to find how many groups of a size fit into an amount.
- describe a leftover part as a fraction of a group.
- write an answer as a mixed number, like 2 2/3.
Key words
- tape diagram
- A bar split into equal pieces to show amounts and groups.
- batch
- One full amount made by the recipe, which here uses 3 cups of vegetables.
- mixed number
- A whole number and a fraction together, like 2 2/3.
Transcript
- [Instructor] We're told a pasta salad recipe calls for three cups of chopped vegetables. Asha chopped eight cups of vegetables to make batches for an event. Use a tape diagram to determine how many batches of pasta salad Asha can make. Pause this video. Have a go with that.
All right, so one way to think about it, let's make a tape or I guess you could say a bar that represents the eight cups of vegetables that Asha has chopped. So this right over here. I'll write it this way. Eight cups right over here. And we could also represent it as the individual cups.
Let me do it that way too. Maybe I'll do that in a different color just for a little bit of variety. So do it like this, like that. All right. So I want to divide this into, I wanna show the cups here. So what we're doing is that about halfway, maybe a little bit further to the right.
Maybe right here, that looks about halfway. Then half of that. I'm hand drawing it so it's not going to be super exact, but close enough. So let me divide each of these, each of these, each of these, each of these. Okay, I have one, two, three, four, five, six, seven, eight.
They're hand drawn, they should be equal, but you can tell they're not quite, 'cause I hand drew them. But you got the idea. Each of those is a cup. Now we know that there's three cups of chopped vegetables per batch, per batch of the recipe. So for example, let me pick another nice color here.
I'll do green since we're talking about vegetables. That right over there is one batch. That over here is a second batch. So that is one batch. One batch again. And then what is this? What do we have over here? Well, we have two cups, not three. Three would be another full batch.
So this would be two out of the three cups we need. So this would be 2/3 of a batch. So how many total batches of pasta salad can Asha make? What's gonna be 1 plus 1, which is 2 plus 2/3? It's 2 and 2/3 batches. 2 and 2/3 batches is what she can make.
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