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

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

#### 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.