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# Choosing the Most Orange Crystal

Media Type:
Video

Running Time: 1m 45s
Size: 4.8 MB

or

Source: Cyberchase: “A Piece of the Action”

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Collection Credits

### Collection Funded by:

Funding for the VITAL/Ready to Teach collection was secured through the United States Department of Education under the Ready to Teach Program.

In this video segment from Cyberchase, the CyberSquad looks at seven different crystals to determine which crystal displays the largest amount of orange color, and thus has the most power. They find that some crystals have more stripes of certain colors than others but not all the stripes are the same size. The CyberSquad solves the problem by thinking about the stripes as fractional parts of the crystals, and then comparing the fractions to determine the largest one.

Connections

Everyday Math (2004)
Teacher Lesson Guide pp. 541-548
Student Reference, pp. 47-50
Math Journal pp. 356-357, 207

Investigations/Scott Foresman (2006)
Different Shapes, Equal Pieces
Investigation 1, Session 5: pp. 19-21
Investigation 2, Sessions 3 and 4: pp. 29-37
Investigation 3, Sessions 1 and 2, pp. 41-45

Teaching Tips

Here are some Frame, Focus and Follow-up suggestions for using this video in a math lesson.

What is Frame, Focus and Follow-up?

Frame: Sometimes you might have to compare fractions to see which is bigger. Do you know which is more, ½ or ¼? How do you know? How about comparing 1/8 and 2/8? Which is bigger, and how do you know? Are denominators important in comparing fractions likes these? Why? What if fractions have different denominators, like 1/8 and 3/4? How do you go about comparing fractions like that?

Focus: As you watch this video segment, think about how the CyberSquad compares the different amounts of orange on the various crystals. Consider how their knowledge about fractions helps them. Are denominators important? How does the CyberSquad compare fractions with different denominators?

Follow Up: How did the CyberSquad know which crystal had the most orange and thus, the most power? How can you compare fractions that have unlike denominators, like 5/8 and 2/4 for example? What does the denominator in a fraction actually tell us? Can you name three fractions equivalent to 1/2? How could knowing about equivalent fractions be helpful when food shopping?

Transcript

JACKIE: The power crystals!

INEZ: Motherboard said 'the one with the most orange has the most power' - remember? We have to find the one with the most orange.

JACKIE: So which one is that?

MATT: Hmmm, these seem to have a lot. This one has four orange stripes out of a total of...ten.

INEZ: Hey! That sounds like a fraction. It might be a clue. Four over ten.

MATT: And this one has seven out of ten - that's way more than four out of ten!

INEZ: A-Ha!

JACKIE: This one only has four orange stripes out of five.

MATT: I'd say seven out of ten is the most. Let's use this one!

JACKIE: Hold on! We don't know that for sure. We didn't compare my fraction!

MATT: But how can we do that? Four out of ten and seven out of ten are easy to compare because they each have ten equal parts. But four fifths is another kind of fraction.

JACKIE: Well, what if we divided each of my 5 stripes in half...Then we'd have ten stripes like the others right?

INEZ: Ok, but how many would be orange?

MATT: Let's do it and find out.

JACKIE: Looks like 8 stripes are orange now. So four out of five is the same amount as eight out of ten!

MATT: Cool! We can write 4 out of 5 as 8 out of 10.

INEZ: And 8 out of 10 is definitely more than 7 out of 10!

MATT: Bigger fraction, more orange - more power! This one should open the door!

Standards

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