3rd Grade · Number & Operations - Fractions
3.NF.A.2: Place fractions on a number line
3.NF.A.2 is a 3rd grade Common Core math standard in Number & Operations - Fractions. Here’s what it really covers, and how you can help your students learn it.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
The standard
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. b. Represent a fraction a/b on a number line diagram by marking off a lengths 1/b from 0. Recognize that the resulting interval has size a/b and that its endpoint locates the number a/b on the number line.
In plain words
Place fractions on a number line.
Sample questions from student practice
These questions from Bobby's Math Club are the kinds of questions your students will see. You can try answering them to see what a student might see.
Question 1 of 3
The number line from 0 to 1 is cut into equal parts. Which fraction is at point N?
- 3/8
- 5/8
- 4/8
Where students can get stuck
- Counting the tick marks instead of the spaces, so a line from 0 to 1 in fourths, with 5 marks, gets labeled in fifths.
- Drawing unequal spaces on the number line, so the fractions land in the wrong places.
- Thinking fractions only go between 0 and 1, and leaving numbers like 4/4 or 6/4 off the line.
Effective teaching strategies
- Fold a paper strip into equal parts and mark 0 and 1 on it, so students count the spaces between marks and not the marks.
- Ask students to label every jump from 0, so they see that 3/4 is three jumps of 1/4.
- Extend the number line past 1 and place fractions such as 4/4 and 6/4, so students see that fractions are numbers that can be more than 1.
Units that teach this standard
Find where 3.NF.A.2 lands in the program you teach. Each unit has a guide written for families. Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence.
Bridges in Mathematics
enVision Mathematics
Eureka Math²
Everyday Mathematics
i-Ready Classroom Mathematics
Illustrative Mathematics
Into Math
Math Expressions
Reveal Math
Zearn Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Fractions on a number line for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice fractions at home
In Bobby's Math Club, students practice at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free for every family.
See how it works for teachers
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.