3.NF.A.2 Fractions on a  Number Line

Evidence Statement 3.C.6-1  Base explanations/reasoning on a number line diagram (whether provided or constructed by the student in their response) 

Fractions on a Number Line

Part A

Which number line shows a point at 8/6 ?

Circle the point on the number line that shows 8/6.

Two number lines are shown. The first number line shows the numbers 0 through 3 and is partitioned into 6 equal parts in each whole. The second number line shows the numbers 0 through 3 and is partitioned into 8 equal parts in each whole.

Part B

Explain how you know your selection is correct.

Student Copy

Scoring Rubric

Part A

Score of 1 Point- Student selects the number line that correctly shows. 

Student selects the first number line.

Score of 0- Student answer is incorrect or irrelevant.

Part B

Score of 2 Points- Reasoning component- Student response includes at least 2 of the following elements.

·         The numerator is greater than the denominator, so the fraction is going to be greater than 1.

·         The denominator tells you the number of parts in the whole and can be found by counting the number of parts in a whole on the number line.

·         The numerator tells you the number of pieces in the fraction and can be found by counting on the number line.

Sample Student Response- The first number line shows the fraction . I know this because the first number line has six pieces in each whole. The denominator is 6 so I know there need to be six pieces in the whole.  is a fraction greater than 1. I know this because the numerator, 8, is larger than the denominator, 6. The first number line is marked in a spot greater than 1 and number line 2 is marked in a spot that is less than 1.

Score of 1 Point- Student response includes 1 of the elements.

Score of 0 Points- Student response is incorrect or irrelevant.