Domain

Measurement and Data

Cluster

Relate addition and subtraction to length.

Standard(s)

NC.2.MD.6 Represent whole numbers as lengths from 0 on a number line diagram with equally spaced points and represent whole-number sums and differences, within 100, on a number line.

Materials

student form, pencil.

Task

Provide materials to the student.  Read the directions to the student:

Problem 1:  Complete the number line

Problem 2:  Use the number line to solve 12+4=

Problem 3:  Use the number line to solve 16-5=

Continuum of Understanding

Not Yet Proficient

·         Unable to count to 20

·         Unable to write numbers to 20

·         Unable to use a number line to solve addition and subtraction problems.

·         Can complete the first number line but not the addition or subtraction number line.

Checklist for teacher to identify mastery of standard:

Student is able to:

·         Correctly completes the number line.

·         Uses a number line as a tool to solve the problems accurately.

Strategy(ies) Used:

·         Counting Back

·         Counting Up

Progressing

·      Can complete the number line and solve one of the problems correctly.

·      Requires some teacher prompting or assistance to complete the number line and or one of the problems.

Meets Expectation

·      Correctly completes the number line and uses the number line as a tool to solve both the addition and subtraction problems accurately.

Standards for Mathematical Practice

1. Make sense of problems and persevere in solving problems.

2. Reason abstractly and quantitatively.

3. Construct viable arguments and critique the reasoning of others.

4. Model with mathematics.

5. Use appropriate tools strategically.

6. Attend to precision.

7. Look for and make use of structure.

8. Look for and express regularity in repeated reasoning.,