Is Subtracting Integers Just Like Adding Integers?
Subtaction is Exactly the Same as Adding Except...
Before You Look at the Signs You;
KEEP, CHANGE, CHANGE
Keep the 1st Integer the Same
Change the Operation Sign to Addition
Change the Sign of the Second Integer
THEN USE the RULES for ADDITION of INTEGERS
Step 1: Look At Signs of Numbers
If they are the SAME:
- Add Together & Keep the Sign the same.
2 + 5 = 7
(-7) + (-2) = - 9
If the Signs are DIFFERENT:
- Find Number with Largest Absolute Value
- Subtract Smallest Absolute Value from Largest Absolute Value
The answer takes the sign of the Largest Absolute Value
8 + (-17) = ?
- The absolute values of 8 and -17 are 8 and 17.
- Subtracting the smaller from the larger gives 17 - 8 = 9, and since the larger absolute value was 17, we give the result the same sign as -17, so 8 + (-17) = -9.
