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### Course: 4th grade > Unit 8

Lesson 8: Line plots with fractions# Interpreting line plots with fractions

The weights on this line plot are to the nearest 1/8 pound, because there are 8 equal spaces between whole numbers. Each dot represents the weight of one baby. Let's find the difference between the two heaviest babies. Created by Sal Khan.

## Want to join the conversation?

- if you had the answers 6/8 and 3/4, would either of the answers matter to answer the question?(11 votes)
- they are the same fractions exept 3/4 is simplified(5 votes)

- can you sometimes have un even numbers(2 votes)
- My teacher said you can count the spaces between the the the two fractions to get you're answer.(2 votes)
- The weights on this line plot are to the nearest 1/8 pound,because there are 8 equal spaces between whole numbers. Each dot represents the weight of one baby.(2 votes)
- how do I know that its always going to be eight(1 vote)
- how did we get 6/8(1 vote)

## Video transcript

- [Instructor] We're told that the weights of 11 different babies are
recorded on the line plot below and we see there is one, two, three, four, five, six, seven, eight, nine, 10, 11 data points. Each one represents a different baby whose weight is recorded. Each weight was rounded to
the nearest 1/8 of a pound. All right, then they ask us, what is the difference, in weight, between the two heaviest babies? So pause this video and try to figure that out before we work through it together. All right, now where are
the two heaviest babies? So this one out here, this is the heaviest baby, and what is its weight? Well, let's see. Its weight is right over there, and what is that number
or what is that weight? So this is nine and this is 10, and we have one, two, three, four, five, six, seven, eight equal spaces. So each of these is an eighth. So this is nine and one, two, nine and 2/8. So this one is, let me write this. This is nine and 2/8. Another way to think about it is, 2/8 is the same thing as 1/4, 'cause if you think about it, it's one, two, three, four equal spaces. This is also nine and
1/4 of the way to 10, so this is the same thing as nine and 1/4. And then what's the
second heaviest babies? 'Cause we want the weight difference between the two heaviest. So the second heaviest
baby is right over here and we know that it is
eight and a half pounds. So what we really need to do is figure out what is the difference
between nine and 2/8 or nine and 1/4 and eight and a half right over here? So we could set this up as a subtraction. This is going to be nine and, let's call it nine and 1/4, minus, minus eight and a half, and we can actually use this, this, these measurement scales or you can even view this as something of a number line to help us think about this. The difference is this
length right over here. And we could think about
it in terms of eighths, 'cause each of these
hash marks is an eighth, so 1/8, 2/8, 3/8, 4/8, 5/8 and 6/8. So this is equal to 6/8. We could also think about
it in terms of fourths, so this is 1/4, 2/4, and 3/4. So this is equal to 3/4. So what's the difference in weight between the two heaviest babies? It is 3/4 of a pound.