Domain

Operations and Algebraic Thinking

Clusters

Add and subtract within 20.

Analyze addition and subtraction equations within 20.

Standards

NC.1.OA.6 Add and subtract, within 20, using strategies such as:

• Counting on

• Making ten

• Decomposing a number leading to a ten

• Using the relationship between addition and subtraction

• Using a number line

• Creating equivalent but simpler or known sums

NC 1.OA.8 Determine the unknown whole number in an addition or subtraction equation involving three whole numbers.

Materials

SF, cubes or counters, pencil

Task

Provide materials to the student.  Read problem aloud:  Solve the following equation using two different strategies.  14 – 9 =  ?

Continuum of Understanding

Not Yet Proficient

●   Incorrectly solves the problem and does not have strategies that lead to a correct answer

Strategies Used:

q  Trial and Error

q  Counting All

q  Counting On

q  Makes Tens

q  Basic Facts

q  Creates easier or known sums

q  Doubles

q  Doubles +/- 1, 2

q  Other:

Progressing

●   Correctly solves the equation using two different strategies, but uses counting all as a strategy

Meets Expectations

●   Correctly solves the equation using two different strategies that do not include counting all