Utah Core Standards
UT.2.OA. OPERATIONS AND ALGEBRAIC THINKING (2.OA)
Represent and solve problems involving addition and subtraction. Fluently add and subtract within 20 and work with equal groups of objects to gain foundations for multiplication.
2.OA.2. Fluently add and subtract within 20.
2.OA.2.a. Add and subtract within 20 using mental strategies such as counting on; making ten (for example, 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (for example, 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (for example, knowing that 8 + 4 = 12, one knows 12 – 8 = 4); and creating equivalent but easier or known sums (for example, adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
2.OA.2.b. By the end of Grade 2, know from memory all sums of two one-digit numbers.
UT.2.NBT. NUMBER AND OPERATIONS IN BASE TEN (2.NBT)
Understand place value. Use place value understanding and properties of operations to add and subtract.
2.NBT.5. 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.6. Add up to four two-digit numbers using strategies based on place value and properties of operations.
2.NBT.7. Add and subtract within 1,000 using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, and ones and ones, and that it is sometimes necessary to compose or decompose tens or hundreds.
2.NBT.9. Explain why addition and subtraction strategies work, using place value and the properties of operations. Explanations may be supported by drawings or objects.