Adding and Subtracting Rational Numbers 2-2 Objective: Students will add and subtract integers and rational numbers. S. Calahan 2008
Addition of Rational Numbers Same sign – add their absolute values. The sign for the answer will be the same as the addends. Example: (-7) = - 18
Addition of Rational Numbers Different signs – subtract the lesser absolute value from the greater absolute value. The sum has the value of the greater absolute value. Example: 8 + (-9) = -1
Add (-5) = (-4) = = 8
Additive Inverse Property The sum of a number and its additive inverse is 0. Example: 2 + (-2) = 0
Subtraction of Rational Numbers Add its additive inverse: Take the sign of the largest number. Example: 8 – 15 = 8 + (-15) = -7
Subtraction – 8 = (-8) = – (-23) = = – 9 – 6 = -9 + (-6) = -15