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## Arithmetic

### 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.

## 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.