Fried Chicken and... Subtraction?!

 

Scared of subtraction involving negative integers? Don't be - remember, it's just addition in disguise!

The rule for subtraction is:

Add the OpPoSiTe!


Who likes fried chicken? It's one of my all-time favorites. :)

Img: thebittenword.com

So... what does fried chicken have to do with subtracting integers? Check out this cool chart from passyworldofmathematics.com:


Then, solve your problem as an addition problem. Here are a few examples:

-5 - 3 = ?
-5 + (-3) = -8  ---> Both numbers are the same sign, so we can add like normal and keep the sign.

7 - (-2) = ?
7 + 2 = 9   ---> Again, both numbers are the same sign, so we can add like normal and keep the sign.

4 - 8 = ?
4 + (-8) = ?  ---> Now we've got addition with two different signs, so remember to use your absolute values!
The absolute values are 4 and 8. The difference between 4 and 8 is 4. Now, is it negative or positive? Look at the original number that had the greatest absolute value: -8. Since it's negative, we know the answer is -4.

Reminders for integer operations:
- Positive + Positive = Positive
- Negative + Negative = Negative
- Adding two numbers with different signs: Find absolute values. Determine difference between
  absolute values. Use the sign of the number that has the greatest absolute value.
- Change to addition and add the opposite (KEEP, FLIP, CHANGE). *Once you've turned your
   subtraction problem to addition, forget about the subtraction part. You are now solving an addition
   problem and should proceed with the rules above.