Numbers can be represented in many ways: digits, words, Roman numerals, and various bases. Understanding these systems helps when building applications that handle diverse numeric formats.
Positional Notation
In decimal (base 10), each position represents a power of 10. The number 234 means 2×100 + 3×10 + 4×1. This system enables efficient arithmetic but the word forms (two hundred thirty-four) reflect this structure directly.
Named Number Groups
English groups numbers in thousands: thousand, million, billion, trillion, quadrillion. Each group is 1000× the previous. Note: historically, British "billion" meant million million—modern usage follows American convention of thousand million.
Special Cases in English
The teens (eleven through nineteen) have irregular names from Old English. "Hundred" can mean exactly 100 or approximately 100. "Dozen" (12) and "score" (20) are historical groupings still occasionally used.
Decimals and Fractions
Decimals are read digit by digit after "point": 3.14 is "three point one four." Fractions use ordinals: 3/4 is "three fourths." Mixed numbers: 2 3/4 is "two and three fourths." Percentages: 15% is "fifteen percent."