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## 3rd grade

### Unit 6: Lesson 1

Comparing fractions- Comparing fractions with > and < symbols
- Comparing fractions visually
- Compare fractions with fraction models
- Compare fractions on the number line
- Comparing fractions with the same denominator
- Compare fractions with the same denominator
- Comparing unit fractions
- Comparing fractions with the same numerator
- Compare fractions with the same numerator
- Compare fractions with the same numerator or denominator

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# Comparing unit fractions

Sal compares unit fractions using visuals.

## Video transcript

- [Instructor] So which
of the following numbers is greater, 1/3 or 1/5? Pause this video and try to answer that. All right, now let's
think about this together. And the way that I can best think about it is by visualizing them. So let's imagine a whole. So this is a whole right over there. And then let's say that
this is another whole right over there, I'm gonna
try to make these rectangles about looking about the same. And now, how would I represent 1/3? Well, I would divide this whole
into three equal sections. And so I'm gonna try to divide
it into three equal sections. So that's three equal
sections right over there. Now they're supposed to
be three equal sections, these are hand-drawn so
give me a little slack. But one of these three equal
sections, well that's 1/3. So that is 1/3 right over there. Now what about 1/5? Well then I would try to divide
this in five equal sections. So one, two, three, four, and five equal sections. And so 1/5 would be just
one of these fifths. So it would be that right over there. So when you compare it like
this, what's larger 1/3 or 1/5? And if it isn't obvious just yet, I could drag this one over, so that we can compare them, so that we can compare them directly. And you can see very clearly that 1/3 covers more of the whole,
it's a larger fraction of the whole than 1/5 is. So 1/3 is greater than 1/5. And so you might have noticed
an interesting pattern or might start thinking about a pattern. You might have been tempted
when you saw the five here, five is larger than three,
but 1/5 is less than 1/3 or 1/3 is greater than 1/5. And that is generally true, that the larger the denominator, the smaller the fraction is going to be. Why is that? Because you're dividing your
whole into more equal chunks. So if you're only dividing into three, if it's one of three of the
whole, 1/3 of the whole, or if it's one of three
equal chunks of the whole, it's gonna be bigger than one of five equal chunks of the whole. And so based on this, how would you compare these two numbers? How would you compare 2/3 to 2/5? Well, same idea here. 1/3 is bigger than 1/5, so 2/3 is definitely going
to be bigger than 2/5, and you can see it here. 2/3 is that, while 2/5 is that right over there. And I can do another example where I haven't even drawn it out. How would you compare four over six to four over eight? So 4/6 versus 4/8? Well, same idea. 1/6 is larger than 1/8. 1/6 is greater than 1/8, because the denominator here is smaller. We have the same numerator,
but the denominator is smaller. So four of the bigger
things is going to be larger than four of the smaller things. So 4/6 is greater than 4/8.