Teaching the Common Core Math Standards With Hands-On Activities, Grades 3-5 (30 page)

Activity: Finding Equivalent Fractions

Working in pairs or groups of three on a Web site, students will generate equivalent fractions.

Materials

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

Procedure

1.
Instruct students to go to
http://nlvm.usu.edu/
. They should click in the grades “3–5” column on the “Number and Operations” row and then scroll down and click on “Fractions-Equivalent.”

2.
Explain that students will see a circle, square, or rectangle divided into equal parts. Some of the parts will be shaded. They will also see a fraction relating the number of shaded parts to the total number of parts.

3.
Demonstrate how to find a new name for the fraction by using the arrow button to select the number of parts. The up arrow divides the figure into a larger number of equal parts. The down arrow divides the figure into a smaller number of equal parts.

• Show your students that when the figure is divided into the correct number of parts, the shading will cover equal-sized parts entirely with no overlaps. The number of shaded parts represents the numerator. The number of equal parts represents the denominator. Note that students may recognize equivalent fractions without having to move the up and down arrows. In this case, they may simply enter the numerator and denominator in the spaces after the equal sign and then check their answers.
  
• Students are to complete the equivalence, and the computer will state if the equivalence is correct. If students are incorrect, the computer will provide hints for completing the equivalence correctly.
  

4.
Instruct students to click on “New Fraction.”

5.
Allow time for your students to explore at least five different fractions, writing two equivalent fractions for each. Students should record their answers so that they may refer to them during Closure.

Closure

Discuss students' results. Ask your students to write an explanation of how they can tell that two fractions are equivalent.

Number and Operations—Fractions: 4.NF.2

“Extend understanding of fraction equivalence and ordering.”

2. “Compare two fractions with different numerators and different denominators, e.g., by creating common denominators or numerators, or by comparing to a benchmark fraction such as
. Recognize that comparisons are valid only when the two fractions refer to the same whole. Record the results of comparisons with symbols
or
and justify the conclusions, e.g., by using a visual fraction model.”

Background

Students may compare fractions in three ways:

• Find the common denominator and write equivalent fractions. Then they can compare the numerators. For example, if a student is asked to compare
  and
  , she may say that
  and realize that because
  ,
  .
  
• Create a model, comparing
  to
  , as shown below.
  

  

  

• Compare a fraction to another fraction. For example,
  can be compared to
  by understanding that
  and
  ; therefore
  .