NC.2.OA.1 Represent and solve addition and subtraction word problems, within 100, with unknowns in all positions, by using representations and equations with a symbol for the unknown number to represent the problem, when solving:
NC.2.OA.1.a One-Step problems:
NC.2.OA.1.a.1 Add to/Take from-Start Unknown
NC.2.OA.1.a.2 Compare-Bigger Unknown
NC.2.OA.1.a.3 Compare-Smaller Unknown
NC.2.OA.1.b Two-Step problems involving single digits:
NC.2.OA.1.b.1 Add to/Take from- Change Unknown
NC.2.OA.1.b.2 Add to/Take from- Change Unknown
Add and subtract within 20.
NC.2.OA.2 Demonstrate fluency with addition and subtraction, within 20, using mental strategies.
NC.2.MD.5 Use addition and subtraction, within 100, to solve word problems involving lengths that are given in the same units, using equations with a symbol for the unknown number to represent the problem.