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:
- Khan Academy: Fractions on a Number Line
- Learn Zillion – Place Fractions on a Number Line:\
- Have your child show different unit fractions on a number line (Ex: 1/4, 1/6, 1/8 )