Common Core Alignment: Basic Subtraction (Within 20)

1.OA.5:

Operations And Algebraic Thinking

Add And Subtract Within 20.

Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).

1.OA.6:

Operations And Algebraic Thinking

Add And Subtract Within 20.

Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).

2.OA.2:

Operations And Algebraic Thinking

Add And Subtract Within 20.

Fluently add and subtract within 20 using mental strategies.2 By end of Grade 2, know from memory all sums of two one-digit numbers.