Math 1 · Lesson 3 · Step One · part 6 of 9
Negatives: think owe and have
Once every subtraction is "add the opposite," you are only ever adding .
Negatives: think owe and have
Once every subtraction is "add the opposite," you are only ever adding. So you do not need a page of sign rules. Think of a balance: positive is money you have, negative is money you owe.
−3 + (−4)Owe 3 and owe 4. Owe 7. So −7.
5 + (−2)Have 5, owe 2. Have 3. So 3.
−8 + 3Owe 8, have 3. Still owe 5. So −5.
Same signs: add the amounts, keep the sign (owe and owe, or have and have). Different signs: take the difference, and keep the sign of the bigger pile. That is it. No other rules.