is review what we know about line plots,

but apply them in a situation

where some of our data involves fractions.

So they tell us the lengths of some caterpillars

are shown below, and so we can see

that here in the line plot,

just to refresh our minds how to read a line plot,

this tells us that we have two caterpillars

that are four centimeters long.

These three show that we have three caterpillars

that are seven centimeters long.

Each dot represents a caterpillar

whose length we are measuring.

It allows us to see how those lengths are distributed.

For example, we have a lot of caterpillars at this length.

What is that length?

Well we can see that is exactly

half way between four and five,

so that is four and one half centimeters long.

We divide the section between four and five

into two equal sections, and we're going

one of those two equal sections towards five,

so this is four and a half centimeters.

I can ask you some questions.

How many total caterpillars were measured?

Pause this video and think about that.

Well each dot represents a caterpillar measurement,

and we have one, two, three, four, five, six, seven,

eight, nine, 10, 11, 12, 13, 14, 15, 16, 17.

So we have a total of 17 caterpillars.

Now another question we could ask ourselves

is how many of the caterpillars

are five and one fourth centimeters long?

Pause the video and think about that.

Well five and one fourth is going to be more than five,

and what we'd want to do to get to five and one fourth

is divide the interval or the length between five and six

into four equal sections, they already did that,

one, two, three, four, and then we want to go

one of those four equal sections.

So five and one fourth is right over here

and we can see that there's one caterpillar

that is five and one fourth centimeters long.

We can ask ourselves other questions.

How many caterpillars, let me write it over here,

how many have length

more than six and one half centimeters?

Pause the video and try to answer that.

Where is six and a half centimeters?

Well, we can divide the section between six and seven

into two equal sections, and if you go

one of those two equal sections, that is six and a half,

so that is six and a half right over there.

How many have a length more than or greater than

six and a half centimeters?

Well we can see it right over here.

One, two, three, four, five, six.

Six of them do.

And we can even try to answer questions like

how many more have a length

of nine and a half centimeters

than five and one fourth centimeters?

Try to answer that question.

Well nine and a half centimeters,

that's half way between nine and 10, right over there.

We can see two of them have a length of

nine and a half centimeters.

And we already know that one of them

has a length of five and one fourth,

so how many more have nine and a half centimeters

versus five and one fourth?

Well that would be two minus one, or one more.

We have one more caterpillar with a length

of nine and a half centimeters

than we do with five and one fourth.

I'll leave you there.

We have plenty of examples on Khan Academy

for you to practice this.