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## 4th grade

### Course: 4th grade > Unit 10

Lesson 9: Comparing decimals visually# Comparing decimal numbers on a number line

Sal compares decimals on a number line. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

- why would we need them in a line(11 votes)
- Hi, Edwin!

Just like how you count 1 to 2 to 3 to 4, we are also increasing our values as we go right and decrease them as we go down.*The number line is to help us evaluate the location of a number or fraction on a scale. it is also a pointer that if we add, subtract, multiple, or divide said numbers into each other, where they would end up or be on said number line.*

It's not crucial to use a number line in order to do these problems. the number line is mostly a visual representation and a helpful reminder for people who have trouble spotting where their numbers should be.

Thank you so much for the question! have a nice day! :)(6 votes)

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nice(14 votes) - he said lumber line it's ok though(13 votes)
- i keep getting them wrong. can you please explain this more clearly?(5 votes)
- You may want to watch the video again if you haven't already. Concepts take time to sink in. If you are still struggling, you can get help another person.(6 votes)

- so are decibels just negative numbers right? ps. sorry for bad grammar(5 votes)
- why is he saying "10ths" when it is 11(4 votes)
- beacus i need more votes(4 votes)
- i understand this problem very much(3 votes)
- bro really said lumber line(2 votes)
- im confused can you show another strategy if there is one?(2 votes)

## Video transcript

Use a number line to
compare 11.5 and 11.7. So let's draw a
number line here. And I'm going to focus
between 11 and 12, because that's where our
two numbers are sitting. They're 11, and then something
else, some number of 10ths. So this right here is 11. And this right here would be 12. And then let me draw the 10ths. So this would be
smack dab in between. So that would be 11 and
5/10, or that would be 11.5. Well, I've already
done the first part. I've figured out where 11.5 is. It's smack dab in
between 11 and 12. It's 11 and 5/10. But let me find everything else. Let me mark everything
else on this number line. So that's 1/10, 2/10, 3/10,
4/10, 5/10, 6/10, 7/10, 8/10, 9/10, and then 10/10,
right on the 12. It's not completely
drawn to scale. I'm hand-drawing it
as good as I can. So where is 11.7 going to be? Well, this is 11.5, this
is 11.6, this is 11.7. 11 and 7/10. 1/10, 2/10, 3/10,
4/10, 5/10, 6/10, 7/10. This is 11.7. And the way we've
drawn our number line, we are increasing as
we go to the right. 11.7 is to the right of 11.5. It's clearly greater than 11.5. 11.7 is greater than 11.5. And really,
seriously, you didn't have to draw a number
line to figure that out. They're both 11
and something else. This is 11 and 5/10. This is 11 and 7/10. So clearly, this one
is going to be greater. You both have 11, but this
has 7/10, as opposed to 5/10.