A number is a mathematical object used to count, measure, and label. Besides their practical number in english letter, numbers have cultural significance throughout the world.
For example, in Western society, the number 13 is regarded as unlucky, and “a million” may signify “a lot. During the 19th century, mathematicians began to develop many different abstractions which share certain properties of numbers and may be seen as extending the concept. Among the first were the hypercomplex numbers, which consist of various extensions or modifications of the complex number system. Numbers should be distinguished from numerals, the symbols used to represent numbers.
The Egyptians invented the first ciphered numeral system, and the Greeks followed by mapping their counting numbers onto Ionian and Doric alphabets. For systems for expressing numbers, see Numeral system. Numbers can be classified into sets, called number systems, such as the natural numbers and the real numbers. 1, 2, 3, and so on.