## ◂Math Worksheets and Study Guides Second Grade. Subtraction is not Commutative

### The resources above correspond to the standards listed below:

#### Maryland College and Career-Ready Standards

MD.MA.2.OA. Operations and Algebraic Thinking (OA)
2.OA.A. Represent and solve problems involving addition and subtraction.
2.OA.A.1. Major Standard: 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 represent the problem.
2.OA.A.1.1. Ability to explore addition and subtraction with manipulatives to build their conceptual understanding (e.g., snap cubes, subitizing cards, tens frames, hundreds charts, number lines and empty number lines).
2.OA.B. Add and subtract within 20.
2.OA.B.2. Major Standard: Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.
2.OA.B.2.1. Ability to apply counting strategies to develop automatic recall.
2.OA.B.2.2. Ability to use reasoning strategies to make use of known facts (e.g., sums of ten, making ten, doubles, near doubles/inside doubles, doubles plus, counting on).
MD.MA.2.NBT. Number and Operations in Base Ten (NBT)
2.NBT.B. Use place value understanding and properties of operations to add and subtract.
2.NBT.B.5. Major Standard: Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.B.5.1. Knowledge of addition and subtraction fact families.