Tölur
Tölur is the Icelandic term for numbers, the abstract objects used to count, measure, order, and label quantities. In mathematics, tölur form a hierarchy of number systems, including natural numbers, integers, rational numbers, real numbers, and complex numbers, among others. Natural numbers are used for counting, integers extend them to negative values, rational numbers include fractions, real numbers describe continuous quantities and include irrational numbers, and complex numbers combine real and imaginary parts and are central in many areas of mathematics and physics.
The historical development of tölur spans many cultures. Early counting used natural numbers; the invention of
Key properties of tölur include closure under addition and multiplication in many systems, as well as commutativity
Representations of tölur typically use numeral systems. The decimal system is positional, using base ten and