Tennessee Academic Standards
TN.1.OA. Operations and Algebraic Thinking (OA)
1.OA.A. Represent and solve problems involving addition and subtraction.
1.OA.A.1. Add and subtract within 20 to solve contextual problems, with unknowns in all positions, involving situations of add to, take from, put together/take apart, and compare. Use objects, drawings, and equations with a symbol for the unknown number to represent the problem. (See Table 1 - Addition and Subtraction Situations)
1.OA.B. Understand and apply properties of operations and the relationship between addition and subtraction.
1.OA.B.4. Understand subtraction as an unknown-addend problem. For example, to solve 10 – 8 = ___, a student can use 8 + ___ = 10.
1.OA.C. Add and subtract within 20.
1.OA.C.5. Add and subtract within 20 using strategies such as counting on, counting back, making 10, using fact families and related known facts, and composing/ decomposing numbers with an emphasis on making ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9 or adding 6 + 7 by creating the known equivalent 6 + 4 + 3 = 10 + 3 = 13).
1.OA.C.6. Fluently add and subtract within 20 using mental strategies. By the end of 1st grade, know from memory all sums up to 10.
TN.1.NBT. Number and Operations in Base Ten (NBT)
1.NBT.C. Use place value understanding and properties of operations to add and subtract.
1.NBT.C.4. Add a two-digit number to a one-digit number and a two-digit number to a multiple of ten (within 100). Use concrete models, drawings, strategies based on place value, properties of operations, and/or the relationship between addition and subtraction to explain the reasoning used.