Adding and subtracting rational numbers 7th grade math and 6th grade accelerated Math

Adding rational numbers Decimals: line up your decimal points and add straight Fractions: MUST have a common denominator Use Least Common Multiple (LCM) to determine the denominator Multiply the numerator and the denominator by the same number Can be a different number for each fraction (if you have to change more than one)

Rules for adding Rational Numbers 1. When adding with the same sign: add (+) them together and bring the sign with you 2. When adding with different signs: subtract (-) them and take the sign of the larger number

Subtracting rational numbers 1. Keep, Change, Change (KCC): Keep the first number the same, change the sign, and change the sign of the second number Positive  Negative Negative  Positive

Example of adding rational number (fraction)

Example of subtracting rational number (fraction)