Addition and Subtraction Word Problems Task Cards, 2.OA.1 Centers: These 96 UNIQUE TASK CARDS are aligned with the Common Core Standard 2.OA.1. Several types of questions help you assess your students' mastery of addition and subtraction word problems. 2.OA.1. 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 e