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Lesson 4: Subtract within 100

# Addition and subtraction with number lines

Sal figures out which number line matches up with a 2-digit addition or subtraction problem.

## Want to join the conversation?

• Are number lines only good for addition and subtraction? Or do they have other uses?
• Number lines can be an useful tool for looking at single-variable systems. I have used them in most Mathematics courses I have taken so far in college.
• Can you add on a number line?
• Yes. For example, to add 4+3, we can locate 4 on the number line and then move 3 units to the right of 4.

Have a blessed, wonderful day!
• Can you use a number line to solve a division problem?
• Yes, all you need to do is divide that part of number line into required number. If the question is 10/2....take the number line, make it into half (divided by 2) you will get the division at 5. That's the answer.
• How can i get an online teacher
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