Teaching the Common Core Math Standards With Hands-On Activities, Grades 3-5 (12 page)

b.
“Represent a fraction
on a number line diagram by marking off
lengths
from 0. Recognize that the resulting interval has size
and that its endpoint locates the number
on the number line.”

Background

Every fraction can be represented on a number line by marking off equal parts (represented by the denominator of the fraction) and counting off the number of equal parts (represented by the numerator of the fraction).

For example, to locate
on a number line, divide the portion of the number line from 0 to 1 into 4 equal intervals. Then, from 0, count 3 of these intervals and place a dot on the line. Note that the fourth interval is
which is the same as 1.

Activity: Placing Fractions on the Number Line

Working at a Web site, students will move a cursor along a virtual number line to represent fractions.

Materials

Computers with Internet access for students; computer and digital projector for the teacher.

Procedure

1.
Instruct your students to go to
www.mathisfun.com/numbers/fraction-number-line.html
where they will find a virtual number line that ranges from 0 to 1.

2.
Demonstrate how students can locate fractions on the number line. Start at 0 and move the cursor along the number line at the top, stopping at 1 whole. The values of fractions will be displayed. Point out the intervals on the number line and how they correspond to the values of the fractions. Note that the vertical line that highlights the fraction also highlights equivalent fractions.

3.
Instruct your students to locate
on the number line. Give them a chance to locate the fractions, then locate them yourself so that students can see if they are correct.

Closure

Discuss the activity. Ask questions such as the following: What other values are the same as
?
What other values are the same as
?
(
Note:
The previous answers are limited to halves, thirds, fourths, sixths, and eighths, which are the focus of fractions in third grade.) Students should realize that fractions and their equivalent values can be located on the number line.