Use equivalent fractions as strategy to add and subtract fractions.
Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 1/2 = 3/7, by observing that 3/7 < 1/2. (5.NF.2) More information and the complete College and Career Readiness Standards can be found here.