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### Course: 2nd grade > Unit 7

Lesson 3: Line plots# Read line plots

A line plot is a graph that displays data using a number line. To create a line plot, first create a number line that includes all the values in the data set. Next, place an X (or dot) above each data value on the number line. If a value occurs more than once in a data set, place an Xs over that number for each time it occurs.

## Want to join the conversation?

- When he says he will create buckets in the beginning what dose he mean(24 votes)
- 'Buckets' refer to the unit he's using to measure a number on a graph. So if I had 40 suckers and that's counted on a graph my bucket would go to 40.(20 votes)

- Can you use strategies other than number lines to do them?(3 votes)
- Age is a number, so it is better to use number line (age increases after a year, number line is increasing too). However, there is many other ways to visualize it, like graph bars or just table which was used in the video to construct the line plot(9 votes)

- When is it better to use bargraph, line plots, pictogram, or histogram?(4 votes)
- Bar Graphs-Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger. (https://nces.ed.gov/nceskids/help/user_guide/graph/whentouse.asp)

Line plots-Line plots help organize information. Using line plots can help us easily analyze the range and the mode of a set of data (http://studyjams.scholastic.com) USE IF YOU ARE DETERMINING MODE, MEDIAN, MEAN, RANGE

Pictograph: A pictograph uses picture symbols to convey the meaning of statistical information. Pictographs should be used carefully because the graphs may, either accidentally or deliberately, misrepresent the data. This is why a graph should be visually accurate. (https://www.statcan.gc.ca/edu/power-pouvoir/ch9/picto-figuratifs/5214825-eng.htm)

Histographs- I can truly see no difference between Bar graphs and histographs.

If you need me to summarize any information, I'd be honored to assist.(3 votes)

- Why you did not put in 8 9 10?(5 votes)
- He didn't put in 8 or any number higher because the range of the ages aren't higher than 7(6 votes)

- Can the "X" on a line plot mean more than 1?(2 votes)
- If it has an X= this number than yes, it can.(2 votes)

- Will I still be using line plots later on in math?(2 votes)
- You will probably will use line plots later, to figure out mean, median, and mode in maybe 4th or 5th grade.(2 votes)

- Instead of always drawing a line plot horizontally, can we draw it vertically?(2 votes)
- Um, I guess
*so*, but then- how would you*do*it? I really don't know, but _I_ think it's easier to draw it horizontally. =)(0 votes)

- What do you mean by you used more dots than lines?(0 votes)
- from0:22-0:26he meant that in a line plot you use dots to plot the graph yet it is called a line plot(3 votes)

- At1:46, do the dots/x'es have to be color coded to represent each person?(0 votes)
- No, that's just a technique used to make it easier to see which person goes where.(3 votes)

## Video transcript

- [Voiceover] Let's say
we're having a birthday party and these are the kids
at the birthday party. And all the kids, they have
a bunch of different ages, and what we are curious about is how many kids of each age do we have? Well, to help think about that, we can draw what is called a line plot. And I've always viewed the
term line plot a bit confusing because in my brain
you use a lot more dots than you use lines, but let's
look at what a line plot is. So what I will do is I will draw, I guess this involves
a line right over here, I'll draw a line down here, and then I'll create buckets
for each of the ages. So let's see, I have
students here from age three all the way to age seven, so I could say age three, age four, age five, age six, and age seven. I don't have to go to two, or
I don't have to go to eight. There aren't any kids in those ages. Although, I could if I want. And then I look at, well, how many kids do I have of each age? Well, I have one person attending the party, Diya, she's age three. So I would put, I might put an X here, or I could put a dot here. Different line plots would
put different things here. But that shows me that I have, this partier (chuckles) is
age three right over here. Now I have Imran, age five. So that's someone right over here who'd be at age five. You could think of this
dot, this represents Imran, who's age five. Then you have Surya, who's also age five. He's also age five, so that
means we have a second person at the party who is age five. So under age five, we now have two people. This is Imran and this is Surya. Then you have Jasper, who is six. So that's one person who is age six. Then you also have Vikram, who is age six. Whoops, let me do that in that same color. We also have Vikram, who is age six. So let's put him in the age six bucket. Then we have Luke, who is seven. Luke, who is seven. So that would be a dot right over there. And then finally I have
Anya, who's also age six, who is also age six. So just like that, I was
able to take all of the data that I have in this table, and I'm able to put it on this line plot. And the reason why this
line plot is useful is it helps us look at, well, how many of each age do we have? It might be a little bit more confusing to just look at the table here because when you look at the
line plot, it's very clear. Hey look, there's no one
here who is age four. And look, we have the most
people who are age six. And if we asked ourselves a question, if you didn't even have this. Actually, let me just even take it away. If we didn't even have that there, if we didn't have the table
and we just had the line plot, and if someone said hey look, you know, these are ages right over here. This has our ages in years old, and each dot represents a
student who's at the party. So based on this line plot, how many people are more
than five years old? Well, you could look at
this and you could say, okay, more than five years old. That would be six years
old or seven years old. It's not showing anyone who's eight, nine, 10, 11, and on, and on, and on, and on. So let's look at all the dots. Let's look at all the dots here that are more than five years old. There are three six-year-olds and there's one seven-year-old. So there are one, two, three, four people who are old than five years old. You could go the other way around. You could say how many people
are less than five years old? Well then you could say, okay, less than five years old would be either three years old or four years old. And when you look at those dots, you see there's only one dot. Only one person attending the party is less than five years old. Hopefully, you found that interesting.