Algebra - Fractions

Fractions

Definition, Properties, and Operations with Fractions

A fraction is a mathematical way of expressing a part of a whole. It consists of two integers separated by a horizontal bar, written in the form \( \frac{a}{b} \), where:

  • \( a \) is the numerator – it represents how many parts are taken.
  • \( b \) is the denominator – it shows how many equal parts the whole is divided into. \( b \neq 0 \).
Fractions

Types of Fractions

  • Proper Fraction: \( a < b \). Value is less than 1.
  • Improper Fraction: \( a \geq b \). Value is equal to or more than 1.
  • Mixed Number: A combination of a whole number and a proper fraction (e.g., \( 2\frac{1}{3} \)).
  • Equivalent Fractions: Different fractions that represent the same value (e.g., \( \frac{1}{2} = \frac{2}{4} \)).

Basic Operations on Fractions

Addition (Different Denominators):

\[ \frac{a}{b} + \frac{c}{d} = \frac{ad + bc}{bd} \]

Subtraction (Different Denominators):

\[ \frac{a}{b} - \frac{c}{d} = \frac{ad - bc}{bd} \]

Multiplication:

\[ \frac{a}{b} \cdot \frac{c}{d} = \frac{ac}{bd} \]

Division:

\[ \frac{a}{b} \div \frac{c}{d} = \frac{a}{b} \cdot \frac{d}{c} = \frac{ad}{bc} \]

Conversions and Simplification

Mixed Number to Improper Fraction:

If \( a \frac{b}{c} \) is a mixed number, then:

\[ a \frac{b}{c} = \frac{ac + b}{c} \]

Reducing to Lowest Terms:

Divide the numerator and denominator by their greatest common divisor (GCD):

\[ \frac{12}{16} = \frac{12 \div 4}{16 \div 4} = \frac{3}{4} \]

Comparing Fractions:

Use common denominators or decimal conversion.

\[ \frac{2}{5} = 0.4,\quad \frac{3}{8} = 0.375 \Rightarrow \frac{2}{5} > \frac{3}{8} \]

Applications of Fractions

  • Used in measuring ingredients in cooking and baking.
  • Common in financial calculations like taxes, interest, and discounts.
  • Widely used in construction, engineering, and art for scaling and proportions.
  • Essential in understanding probabilities, ratios, and percentages.

Why It Matters

Mastering fractions is fundamental in mathematics and daily life. Whether you're analyzing data, managing money, or cooking a recipe, fractions help interpret and solve real-world problems accurately.

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