Free Printable Second Grade Math Worksheets with Correlations to the ... Operations and Algebraic Thinking 2.OA Represent and solve problems involving addition and subtraction. Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to ...