Understand a fraction as a number on the number line; represent fractions on a number line diagram

a.  Represent a fraction 1/b on a number line diagram by defining the interval from 0 to 1 as the whole and partitioning it into b equal parts. Recognize that each part has size 1/b and that the endpoint of the part based at 0 locates the number 1/b on the number line.

[divider] [/divider] Students are able to… 

  • Use fraction strips to find fractional parts on a number line.
  • Label intervals and points on the number lines. Intervals are unit fractions.
  • Demonstrate understanding that the distance from zero to one represents one whole.
  • Reason and justify the location of unit fractions by folding paper strips or on a number line.

[divider] [/divider] Students are able to…because teachers:

  • Provide students with fraction strips and number lines and ask students to transfer the parts from the fraction strip to the number line.
  • Model labeling unit fraction intervals on the number line.
  • Ask students to use unit fraction intervals to “count” and label each division from zero to one.

[divider] [/divider] Questions to ask students:

  • See if students can correctly subdivide a number line with a distance from 0 to 1 into equal parts.
  • Ask students, “How they would represent one-fourth on a number line?”
    • Sample answer that indicates understanding: Student correctly describes drawing or draws a number line from 0-1 and partitions the distance into four equal parts and identifies that the part starting at 0 represents one-fourth.
    • Sample answer that indicates an incomplete understanding or a misconception: Student partitions the number line by drawing four lines, resulting in 5 equal parts, or parts are not equal.
  • Ask students to compare one-fourth on their number line to one-fourth of a rectangle.
    • Sample answer that indicates understanding: Both models have 1 whole that is partitioned into 4 equal parts, and one of those parts would be one-fourth.

[divider] [/divider] FSA Notes

Cognitive Complexity Level: 2 – Basic Application of Skills and Concepts

Achievement Level Descriptors:

2- identifies the fraction on the number line where the increments are equal to the denominator

3- represents a fraction a/b on a number line by partitioning the number line into b equal parts, and marking off a lengths of 1/b from zero; recognizes that the resulting interval has size a/b and that its endpoint locates the fraction a/b on the number line

4- represents a fraction greater than 1 on a number line

5- represents a set of fractions and fractions greater than 1 with unlike denominators on a number line by partitioning into equal parts

Assessment Limits:

[divider] [/divider] Additional Resources:

Additional in depth content knowledge

Blog Post: Modeling Fractions on a Number Line

Video: Exploring the Number Line Model of Fractions

[divider] [/divider] Sample Formative Assessment Task: 

Resources/Tasks to Support Your Child at Home: