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## Early math review

# Reading bar graphs: dog bones

Sal reads and interprets bar graphs.

## Want to join the conversation?

- what do i do when i need help?? i can't unerderstand the qouitons? thank you(13 votes)
- When you can't understand the questions, try to find a video relating to your problem. Or, you can ask a question here and the community can help you out!(8 votes)

- why do we write zero down in our graphs if its nothing? If we want to know how many apples we have and we have nun than theirs no need to write zero down.(3 votes)
- You write ZERO to show that you know that are ZERO (0) apples. If you write nothing we won't know that you know.

Absence of answer is not always zero. Absence of answer (not writing) may mean that you don't know the answer.

When you write down 0 we'll know that you have the right answer for this question.

Let's have an example:

Let's plot a graph of Nobel prizes won by countries.

How many Nobel Prizes where won by Egyptians ?

If you leave it blank on the graph we'll assume that you DON'T know how many. Actually it's a "right" answer .. you honestly don't know. Absence of information.

If you write down 0 (zero) we'll think that you think Egyptians never won any Nobel Prize and it's wrong since 4 Egyptians have won the Nobel prize.

So, 0 is different from nothing,(4 votes)

- what kinds of uses could we make of a bar graph or graph besides the ones in this video(3 votes)
- All kinds of things. Really you could make a graph out of anything.(8 votes)

- IN khan will we eaver have to create bar grapghs

?\(3 votes)- actually, yes we will. In different skills you will need to know this stuff.(3 votes)

- How can we use bar graphs and charts to make equations?(3 votes)
- Each bar on a graph can represent a number in an addition problem. The sum of the bars is equal to the total amount.(2 votes)

- At2:44, what does category mean?(2 votes)
- a category is a collection of "objects" that are linked by "arrows".(2 votes)

- How do you use a bargraph(3 votes)
- what is 900x298(0 votes)
- okay, so you need to multiply 9 x 298 on paper. you will see it is 2682. now add on two 0s because there were 2 in the equation. hope this helped :)(0 votes)

- Is there different ways to make a bar graph?(2 votes)
- Bar graphs can be vertical or horizontal, but I think other forms have different names. For example, picture graphs are similar to bar graphs, but they aren't classified as bar graphs.(2 votes)

- why is your voice so DEEP?(2 votes)
- because l can.(2 votes)

## Video transcript

- [Voiceover] Some
students traveled by train, airplane, or boat during the summer. This bar graph shows how many students used each type of travel. All right, let's look at this thing. All right, so it tells us that five students traveled by train. It tells us that 10 students
traveled by airplane. Two students traveled by boat. Then we're asked how many
more students traveled by airplane than boat? Well let's see, 10 students
traveled by airplane, two traveled by boat. So how many more is 10 than two? Well we could figure that out by saying, well what's 10 minus two? So 10 minus two is going
to be equal to eight. Eight more students traveled by airplane than by boat. And you could even see it in the bar graph that if you wanted to go from the two who traveled by boat to the 10 who traveled by airplane, you would have to add one, two, three, four, five, six, seven, eight. So eight more traveled
by airplane than by boat. Let's keep going. Sunny, Rover, and Buster buried, Sunny, Rover, and Buster buried bones in the backyard, or in the yard. This bar graph shows how many bones each dog buried. All right, so Sunny buried 10 bones. Rover buried three bones. Buster buried seven bones. How many fewer bones did
Rover bury than Sunny? Let's see, Rover buried three bones, Sunny buried 10 bones. So how many fewer is three than 10? Well to go from 10 to three you have to take away seven. 10 minus seven is three, or 10 minus three is seven. One, two, three, four, five, six, seven. So Rover buried seven
fewer bones than Sunny. 10 minus three is seven. The difference here is seven. Seven. Let's do one more of these. Let's do one more. The weather in November was sunny, cloudy, or rainy. This bar graph shows the number of days of each kind of weather. All right. So we have 18 sunny days in November. We have seven cloudy days in November. We have five rainy days in November. How many rainy days
were there in November? Well I just said it. Look at the rainy category, and this bar graph shows us it goes all the way up to five. There were five rainy days in November. We got it right.