Numerikoj

Numerikoj are the basic objects of counting, measurement, and calculation in mathematics, and they include both the abstract quantities and the symbols used to denote them. In everyday use, numerikoj enable us to compare, measure, and quantify things, as well as to perform arithmetic and model real-world phenomena.

In mathematics, numerikoj are organized into a hierarchy of number systems. Natural numbers (often including zero) are used for counting. Integers extend natural numbers with negative values. Rational numbers include fractions, as ratios of integers. Real numbers encompass rational and irrational values and form a continuous line. Complex numbers combine a real part with an imaginary part and extend the real numbers for solving broader mathematical problems. Each level adds new properties and structures, such as order, density, and completeness, which influence how arithmetic and analysis are applied.

Numerals are the symbols used to write numerikoj. The most common system is decimal (base-10), which uses the digits 0 through 9 and place value to represent large numbers. Other numeral systems, such as binary (base-2), octal (base-8), and hexadecimal (base-16), are widely used in computing and digital systems. The choice of base affects how numbers are written and processed, but the underlying mathematical objects remain the same.

Historically, numerikoj have evolved from early counting methods and varied writing schemes toward the Hindu-Arabic numeral system, which became the global standard for its efficiency and simplicity. Today, numerikoj underpin science, engineering, finance, and computer science, serving as the foundation for computation, measurement, and quantitative reasoning.