How to add and subtract fractions:
1. Find the Lowest Common Multiple (LCM) of both denominators (if different denominators)
ex. 3/4  1/3 denominators: 4 and 3 LCM of 4 and 3: 4, 8, 12, 16 and 3, 6, 9, 12, 15 LCM = 12 2. Change both to equivalent fraction with LCM as denominator. 3/4 x 3 = 9/12 1/3 x 4 = 4/12 3. Replace the equivalent fractions in the question and subtract the numerators only: 9/12  4/12 = 5/12 4. Simplify and reduce, if possible. 
