Tennessee Academic Standards
TN.1.OA. Operations and Algebraic Thinking (OA)
1.OA.B. Understand and apply properties of operations and the relationship between addition and subtraction.
1.OA.B.3. Apply properties of operations (additive identity, commutative, and associative) as strategies to add and subtract. (Students need not use formal terms for these properties.)
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.