Rules for Adding & Subtracting Integers

1. Rules for Adding & SubtractingIntegers

2. Adding & Subtracting Integers Any SUBTRACTION problem can be expressed as an ADDITION problem by… “ADDING THE OPPOSITE” 16 – 10 becomes? 16 + (-10) -26 – 13 becomes? -26 + (-13) 15 – (-22) becomes? 15 + (+22) -42 – (-14) becomes? -42 + (+14)

3. METHOD 1 – SAME SIGN When adding integers with the SAME SIGN (i.e. both positive or both negative) Example: -122 + (-234) • Make both integers positive(absolute value!) • ADD the numbers • If the original integers were POSITIVE, the final answer is POSITIVE • If the original integers were NEGATIVE, the final answer is NEGATIVE 122+ 234 356 Nope! Yup! Answer: -356

4. METHOD 2 – DIFFERENT SIGN When adding integers with DIFFERENT SIGNS Example: 122 + (-234) • Make both integers positive(absolute value!) • SUBTRACT the smaller from the larger • If the larger integer was POSITIVE, the final answer is POSITIVE • If the larger integer was NEGATIVE, the final answer is NEGATIVE 234– 122 112 Nope! Yup! Answer: -112