Domain

Operations and Algebraic Thinking

Clusters

Represent and solve problems

Understand and apply the properties of operations

Add and subtract within 20

Standards

NC.1.OA.1 Represent and solve addition and subtraction word problems, within 20, with unknowns, by using objects, drawings, and equations with a symbol for the unknown number to represent the problem, when solving:

• Add to/Take from-Change Unknown

• Put together/Take Apart-Addend Unknown

• Compare-Difference Unknown

NC.1.OA.4 Solve an unknown-addend problem, within 20, by using addition strategies and/or changing it to a subtraction problem.

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

Add to/Change Unknown

Materials

SF, cubes or counters, pencil

Task

Provide materials to the student.  Read the problem to the student:  12 pennies were in the piggy bank.  Mary put some more pennies in the piggy bank.  Now there are 20 pennies in the piggy bank.  How many pennies did Mary put in the piggy bank? Write a number sentence that matches this story.  Use a symbol for the unknown number.

Once an equation is written, say:   Solve the problem and show your thinking with pictures, numbers, or words.

Continuum of Understanding

Not Yet Proficient

Response includes 0-1 of the descriptors in “Meets Expectations”

Strategies Used:

q  Trial and Error

q  Counting All

q  Counting On

q  Think-Addition

q  Makes Tens

q  Basic Facts

q  Creates easier or known sums

q  Doubles

q  Doubles +/- 1, 2

q  Other:

Progressing

Response includes 2 of the descriptors in “Meets Expectations”

Meets Expectations

Response includes all the descriptors in “Meets Expectations”

·         Correctly solves the problem: 8 pennies

·         Clearly explains using strategies such as basic facts, near-doubles, making tens and/or the relationship between addition and subtraction (instead of counting all).

·         Equation is accurate (e.g., 12 + * = 20; 20 = 12 + *)