Learn on PengienVision, Mathematics, Grade 4Chapter 9: Understand Addition and Subtraction of Fractions

Lesson 2: Decompose Fractions

Property.

Section 1

Representing Fraction Decomposition with Visual Models

Property

The decomposition of a fraction into a sum of unit fractions can be represented by three connected models: a visual tape diagram, a schematic number bond, and a symbolic addition sentence.
All three models represent the same core equation:

ab=1b+1b++1ba times\frac{a}{b} = \underbrace{\frac{1}{b} + \frac{1}{b} + \dots + \frac{1}{b}}_{a \text{ times}}

Examples

Section 2

Decomposing Mixed Numbers into Wholes and a Fraction Part

Property

A mixed number AbcA \frac{b}{c} is visually represented by AA wholes, where each whole is equivalent to cc\frac{c}{c}, plus the fractional part bc\frac{b}{c}.

Examples

Section 3

Decompose a Fraction into a Sum of Fractions

Property

A fraction ab\frac{a}{b} can be decomposed into a sum of smaller fractions with the same denominator, such as ab=xb+yb\frac{a}{b} = \frac{x}{b} + \frac{y}{b}, where x+y=ax + y = a.

Examples

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

Representing Fraction Decomposition with Visual Models

Property

The decomposition of a fraction into a sum of unit fractions can be represented by three connected models: a visual tape diagram, a schematic number bond, and a symbolic addition sentence.
All three models represent the same core equation:

ab=1b+1b++1ba times\frac{a}{b} = \underbrace{\frac{1}{b} + \frac{1}{b} + \dots + \frac{1}{b}}_{a \text{ times}}

Examples

Section 2

Decomposing Mixed Numbers into Wholes and a Fraction Part

Property

A mixed number AbcA \frac{b}{c} is visually represented by AA wholes, where each whole is equivalent to cc\frac{c}{c}, plus the fractional part bc\frac{b}{c}.

Examples

Section 3

Decompose a Fraction into a Sum of Fractions

Property

A fraction ab\frac{a}{b} can be decomposed into a sum of smaller fractions with the same denominator, such as ab=xb+yb\frac{a}{b} = \frac{x}{b} + \frac{y}{b}, where x+y=ax + y = a.

Examples