By the end of this lesson, you will be able to:
- Recognize and generate equivalent fractions
- Use visual models to understand equivalent fractions
- Apply the multiplication and division properties of fractions
- Simplify fractions to lowest terms
- Solve problems involving equivalent fractions
Equivalent Fractions: Fractions that represent the same value or portion of a whole.
Visual Models: Pictures, pie charts, and number lines that help understand fraction relationships.
Properties: Rules that help create and identify equivalent fractions.
In this lesson, we'll explore equivalent fractions using visual models and mathematical properties. We'll start with simple examples and gradually build to more complex problems.
• Multiplication Property: \(\frac{a}{b} = \frac{a \times n}{b \times n}\) where \(n \neq 0\)
• Division Property: \(\frac{a}{b} = \frac{a \div n}{b \div n}\) where \(n \neq 0\)
• Cross Product Rule: \(\frac{a}{b} = \frac{c}{d}\) if \(ad = bc\)
When we multiply both the numerator and denominator by the same number, we're essentially multiplying by 1. This doesn't change the value of the fraction, just how it looks.
\(\frac{1}{2}\) - one half of a whole
\(\frac{1 \times 2}{2 \times 2} = \frac{2}{4}\)
\(\frac{1 \times 3}{2 \times 3} = \frac{3}{6}\)
When you see an equation like \(\frac{a}{b} = \frac{c}{d}\), you can use cross multiplication to solve for the unknown value.
From 3 to 9: \(3 \times 3 = 9\)
\(2 \times 3 = 6\)
\(2 \times 9 = 18\) and \(3 \times 6 = 18\) ✓
Multiply both numerator and denominator by the same number:
\(\frac{3}{4} = \frac{3 \times 2}{4 \times 2} = \frac{6}{8}\)
\(\frac{3}{4} = \frac{3 \times 3}{4 \times 3} = \frac{9}{12}\)
\(\frac{3}{4} = \frac{3 \times 4}{4 \times 4} = \frac{12}{16}\)
Find the Greatest Common Factor (GCF) of 24 and 36:
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
GCF = 12
\(\frac{24 \div 12}{36 \div 12} = \frac{2}{3}\)
Numerators: 1, 2, 3, 4, 5, 6 (counting by 1)
Denominators: 5, 10, 15, 20, 25, 30 (multiples of 5)
Each fraction is equivalent to \(\frac{1}{5}\) multiplied by 1, 2, 3, 4, 5, 6