Primary Standards:

MAFS.1.OA.3.6 Add and subtract within 20, demonstrating fluency for addition and subtraction within 10.  Use strategies such as counting on; making a ten; decomposing a number leading to a ten; using the relationship between addition and subtraction; and creating equivalent but easier or known sums.

MAFS.1.OA.3.5 Relate counting to addition and subtraction (e.g., by counting on 2 to add 2)

MAFS.1.OA.2.3 Apply properties of operations as strategies to add and subtract.  Example: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known.  (Commutative property of addition)

Content Knowledge:

It is not expected students will attain fluency with facts from this Unit within the timeframe of a single Unit.  Fluency should be focused on and assessed throughout the year using games, centers, etc.  It is the goal of the standard that students attain fluency with facts within totals of 10 by the end of the year.

Students in first grade will extend the counting on and counting back strategies beyond the facts within 5 they worked with in kindergarten.  They will also extend counting on and counting back by 2.

Students in this Unit will begin to understand and apply the Commutative property of addition to recognize that they can use known facts to solve unknown or more difficult facts.  For example, if 2 + 5 is known, then that knowledge could be applied to solve 5 + 2.  Students may also build on this understanding to recognize when it is appropriate to count on, for example, 7 + 2 can easily be solved by counting on, however 2 + 7 would not be as easy or efficient.  This understanding can also be used to begin to recognize the relationship between addition and subtraction facts.  Knowing 5 + 2 = 7 can be used to solve 7 – 2 = ? by either counting back 2, or seeing it as a missing addend problem,   ? + 2 = 7 These understandings will not be mastered in this Unit.  Students should begin to explore and recognize these relationships and continue to further understand them throughout subsequent units.


GCG 1 – Learning Goal: As a mathematician, I can Count on (by 0, 1, 2) Fluency within 10 MAFS.1.OA.3.6, MAFS.1.OA.3.5, MAFS.1.OA.2.3

  • Step 1: Direct Model Counting on by 0, 1, 2 with counters (within 10)
  • Step 2: Count on by 0, 1, 2 with a number line (within 10)
  • Step 3: Count on by 0, 1, 2 using an equation

GCG 2 – Learning Goal: As a mathematician, I can Count Back (by 0, 1, 2) Fluency within 10 MAFS.1.OA.3.6, MAFS.1.OA.3.5, MAFS.1.OA.2.3

  • Step 1: Direct Model Counting Back by 0, 1, 2 with counters (within 10)
  • Step 2: Count Back by 0, 1, 2 with a number line (within 10)
  • Step 3: Count Back by 0, 1, 2 using an equation

GCG 3 – Learning Goal: As a mathematician, I can Commutative Property Fluency within 10 MAFS.1.OA.3.6, MAFS.1.OA.2.3

  • Step 1: Direct Model the Commutative Property with counters (within 10)
  • Step 2: Use Number Bonds to represent the Commutative Property (within 10)
  • Step 3: Use an equation to represent the Commutative Property (within 10)