Equivalent Fractions Lesson 2
Use Cuisenaire rods to explore fractional relationships. This lays the foundation for work with challenging fraction concepts like equivalence.
To begin the lesson, give students one set of Cuisenaire rods (either homemade or commercial) and a few minutes to explore the materials.
Ask them "What do you notice?" Examples of things students might mention include:
Distribute the Lesson 2 Fraction Activity Sheet (download from Materials section above). Work together as a class to model the situation where the red is equal to 1. Ask students to grab a red rod and ask:
Direct students to model this relationship with the rods. (See diagram)
Using the lime green as one whole, work together with the students to find how many white rods it takes to equal one lime green rod.
Using the purple as one whole, ask:
Teacher notes - This activity is used to help students recognize the structure of fractions and build equivalence (SMP 7). For example: When the purple rod represents one whole unit, it takes 4 white rods to equal the purple. Therefore, each white rod equals 1/4 of the purple. It takes 2 red rods to equal the purple, so each red is 1/2 of the purple. (Extension: two whites = one red or 2/4 = 1/2.)
At this point determine which students need more guided practice and which are ready to work independently. Circulate as they work and monitor for understanding.
Individual/small group work:
Dark green = 1 whole (See teacher notes below.)
Teacher notes - This activity is used to help students recognize the structure of fractions and build equivalence (SMP 7). For example: When the dark green rod represents one whole unit, it takes 6 white rods to equal the dark green. Therefore, each white rod equals 1/6 of the dark green whole. It takes 3 red rods to equal the dark green, so each red is 1/3 of the dark green whole. (Extension: Two whites = one red or 2/6 = 1/3.)
This is a great opportunity to formatively assess students by observing and listening to students work. Use students' work to facilitate discussion in the class. Have student pair-share their thinking by presenting on one of the questions on the activity sheet.
To summarize/synthesize what they have hopefully noticed about the structure of the fractions (SMP 7), discuss the following questions:
"How do the unit fractions we created using the rods help us understand numbers less than one whole? Will these numbers help us solve problems in our everyday lives?" [Students might talk about sharing pizza among 4 friends. Each friend would get ¼ of the pizza.]
"Let's think about the rods in a different way.
Exit Ticket (SMP 3):
Sarah thinks that two white rods are ⅓ of a dark green. Judd thinks that two whites are 2/6 of the dark green. Who do you agree with and why?
Leave your thoughts in the comments below.
Create and use fraction strips to discover name fractions and compare two unit fractions.
Students generate and explore equivalent fractions using Cuisenaire rods.
Reason and develop an understanding of how to place equivalent fractions on a number line.
Fabulous, works every time!
CCSS, Content Standards to specific grade/standard
CCSS, Standards for Mathematical Practices
PtA, highlighted Effective Teaching Practice and/or Guiding Principle CCSS