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## Arithmetic

### Course: Arithmetic>Unit 18

Lesson 7: Intro to subtracting negative numbers

# Subtracting with integer chips

Let's model subtraction expressions using positive and negative integer chips. To subtract, we'll take away the appropriate number of chips. What if we don't have enough chips to take away? We can add as many zero pairs as we need, because they don't change the value of the expression. Created by Sal Khan.

## Want to join the conversation?

• I understand what he wants us to learn, but how is this helpful? Here is an example when you would use it.

Bill is in the grocery store. He notices the milk costs \$5. He only has \$3. So he pulls out he note book and pencil. He draws 3 positive number chips. And then draws 5 negative number chips. Now he knows he is in debt by \$-2.

I could've been able to figure that out mentally WAAAY quicker. XD
• When will we ever use negative numbers in life?
• Like if something was below ground or below sea level, or even if you have negative balance for money.
• This is very easy for 7th grade work.
• The last one made no sense but its so easy lol.
• the reason why they show us this is to prepare us to be able to subtract a negative. this website's lessons are built on understanding the logic behind the simplest things, so they make sense, and are not just something we do in class.
• Math also is important for coding. This is the reason it helps me. I plan coding will be my major. I do javavscript and python
(1 vote)
• This is tooooooo easy tbh
(1 vote)
• YEET? WHY DOES THatvibdcuibfiuesbhsbfhj
(1 vote)
• i'm in 5th grade this is really confusing but my teacher assigned it so can someone explain it
(1 vote)
• I come back because it says I have not finished this unit yet. Or maybe I didn't finish some of the exercises huh? So here I am, rewatching these videos.
(1 vote)