1.OA.C.6 Teacher Editions
CCSS.MATH.CONTENT.1.OA.C.6
:"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)."
Our Take: Students will solve addition and subtraction problems within 20 through various strategies. For example, the student may use double facts to efficiently solve an addition problem. When finding the sum of 5 and 6, the student can use his knowledge of double facts by breaking 6 down to 5 and 1, resulting in this equation: 5 + 6 = 5 + 5 + 1 = 10 + 1 = 11). Students also quickly use addition and subtraction facts within 10.
These teacher editions can help students practice this Common Core State Standards skill.
