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### Course: Arithmetic > Unit 4

Lesson 3: Fractions on the number line# Finding 1 on the number line

Sal locates 1 on a number line labeled with 0 and a unit fraction.

## Want to join the conversation?

- How is it four fourths?(6 votes)
- 4 fourths is the fraction 4/4. If you do the division, you get 1.

Remember, the denominator of a fraction always tells you how many pieces (in this case fourths) that you need to have one whole unit.

If you have a whole pizza (so 1 pizza) and you cut it into 8 equal slices. Each slice = one eight or 1/8. And all the pieces together = 8 eights = 8/8 = 1 pizza.

Hope this helps.(11 votes)

- how does one be 4/4's(7 votes)
- Because if the denominator (the bottom one) and the numerator (the top one) are the same, it is equal to 1. Hope that helps!(6 votes)

- tysm for making these sorry is your name sal? ty any way ty mean thank you just in case(6 votes)
- Yes, the creator of these videos (and of khan academy), is named Sal Khan(3 votes)

- would 8/4 be 2?(4 votes)
- Yup. If you divide it it would be 8/4 = 2/1 and 2/1 = 2.(4 votes)

- so a 1 doesn't always have to be on the end?😕(•_•)🐻(2 votes)
- Not at all! Remember the number lines from kindergarten? They went to ten or twenty, but those little "<>" marks on the end are called rays, and that means each line can go on forever!(8 votes)

- This is hard Ahhh!(4 votes)
- Okay, since you need help. basically he is saying that it can be ANY NUMBER as long as the Numerator and the Denominator both match! For Example: 12/12 would equal 1. and 3/3 also equals to 1! I hope this helped!(1 vote)

- Emma said i am funny(3 votes)
- I don’t get it(3 votes)
- Well, let's say you have 6/4 and the denominator is smaller than the numerator, so you have more than one whole and the denominator is telling how many parts you will need to make a whole and the numerator is the parts, so you have a whole because the 6/4 is a whole and an extra two parts. Sorry if this isn't very clear but I hope this helps!(2 votes)

- What if you are given three-digit numbers?(2 votes)
- Well, let's say you have 6/4 and the denominator is smaller than the numerator, so you have more than one whole and the denominator is telling how many parts you will need to make a whole and the numerator is the parts, so you have a whole because the 6/4 is a whole and an extra two parts. Sorry if this isn't very clear but I hope this helps!(3 votes)

- Hơ í it four fourths(2 votes)

## Video transcript

- [Instructor] I'm here at
the Khan Academy exercise called Find One on the Number Line and they're asking us to do exactly that. It says, "Move the dot to
one on the number line," and it's a little interactive dot that I can move around. And so, let's think
about how I would do it and I always encourage you, pause this video and see at least how you would think about doing it or put your finger on the
screen where you think one is and then we'll work through it together. All right. So they've told us where zero is and they've told us
where seven fourths is. So one thing I could do is I could say well how many
of these equal spaces does it take me to get
from zero to seven fourths. So let's see it's one, two,
three, four, five, six, seven. So if it takes seven equal
spaces to get to seven fourths, that means that each of
these spaces is one fourth because then it would be
one fourth, two fourths, three fourths, four fourths,
five fourths, six fourths, and seven fourths. All right, we're making
some good progress. So where would one be? Well, one would be four fourths. So we would go one fourth,
two fourths, three fourths, and then four fourths. So that's where one is. So the important thing to
realize is the only way we knew that each of
these, each of these gaps, or each of these spaces
from one hash to the next, the way that we knew that
each of those is a fourth is by saying hey look,
seven of those equal spaces get us to seven fourths, so each of these must be a fourth. So four of those, four
fourths, would be equal to one. Let's do another example. So here, we're said,
we're told to move the dot to one on the number line. So put your finger on where
that would be on the screen. Pause the video and do that. All right. In some ways this is a little bit easier because they told us that going from zero to the next little cross or
hash, I guess you could say, whatever you want to call
these things, is one sixth. So what is one? Well, one or one whole is six sixths. So this is one sixth,
two sixths, three sixths, four sixths, five sixths,
and then six sixths. So there we go. That is where is one
is on this number line.