A fraction represents a part of a whole, written as a numerator over a denominator (a/b).
Fractions express division of one quantity by another. The numerator (top number) represents the number of parts taken, and the denominator (bottom number) represents the total number of equal parts. Fractions can be proper (numerator < denominator), improper (numerator โฅ denominator), or mixed (whole number plus fraction). Equivalent fractions, simplification, and operations (+, โ, ร, รท) with fractions are essential arithmetic skills.
Fractions were used by ancient Egyptians as early as 1800 BCE, though they only used unit fractions (1/n). The Babylonians used sexagesimal fractions (base 60). The Hindu-Arabic numeral system enabled the modern fraction notation. The horizontal fraction bar was introduced by mathematician Fibonacci in his 1202 book "Liber Abaci."