Section 1
Introduction: A Fraction of a Fraction
Property
Finding a fraction of another fraction means you are taking a part of an existing part. For example, taking one-half of a one-half piece results in a one-fourth piece of the original whole.
In this Grade 5 lesson from Illustrative Mathematics Chapter 3, students learn to interpret and represent a unit fraction of a unit fraction using diagrams, building toward the concept of multiplying two fractions. Using a real-world context like a pan of macaroni and cheese, students draw and explain area diagrams and tape diagrams to find fractional quantities such as one-fifth of one-half. This lesson aligns with standard 5.NF.B.4.a and prepares students to connect visual representations to multiplication expressions in later lessons.
Section 1
Introduction: A Fraction of a Fraction
Finding a fraction of another fraction means you are taking a part of an existing part. For example, taking one-half of a one-half piece results in a one-fourth piece of the original whole.
Section 2
Procedure: Modeling a Unit Fraction of a Unit Fraction
To find a unit fraction of another unit fraction, you can model the first fraction with an area model, then take a fractional part of that shaded area. This shows how one small piece relates to the whole.
Expand to review the lesson summary and core properties.
Section 1
Introduction: A Fraction of a Fraction
Finding a fraction of another fraction means you are taking a part of an existing part. For example, taking one-half of a one-half piece results in a one-fourth piece of the original whole.
Section 2
Procedure: Modeling a Unit Fraction of a Unit Fraction
To find a unit fraction of another unit fraction, you can model the first fraction with an area model, then take a fractional part of that shaded area. This shows how one small piece relates to the whole.