Roman numerals
[videos]
The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing
…
Image: Cutty Sark Rom Num
Spanish Real using "IIII" instead of "IV" as regnal number of Charles IV of Spain
Timetable on a shop window in
Vilnius
Binary number
[videos]
In mathematics and digital electronics, a binary number is a number expressed in the base-2 numeral system or binary
…
Arithmetic values represented by parts of the Eye of Horus
Senary
[videos]
The senary numeral system (also known as base-6 or heximal) has six as its base. It has been adopted independently by a
…
Image: Chinesische.Zahl.Dre i
34senary = 22decimal, in senary finger counting
Greek numerals
[videos]
Greek numerals, also known as Ionic, Ionian, Milesian, or Alexandrian numerals, are a system of writing numbers using
…
Example of the early Greek symbol for zero (lower right corner) from a 2nd-century papyrus
Hexadecimal
[videos]
In mathematics and computing, hexadecimal (also base 16, or hex) is a positional numeral system with a radix, or base,
…
Hexadecimal finger-counting scheme.
Image: Bruce Martin hexadecimal notation proposal
Parity (mathematics)
[videos]
In mathematics, parity is the property of an integer's inclusion in one of two categories: even or odd. An integer is
…
Image: Parity of 5 and 6 Cuisenaire rods
Negative number
[videos]
In mathematics, a negative number is a real number that is less than zero. Negative numbers represent opposites. If
…
This thermometer is indicating a negative
Fahrenheit temperature (−4°F).
A visual representation of the addition of positive and negative numbers. Larger balls represent numbers with greater magnitude.
Factorization
[videos]
In mathematics, factorization (also factorisation in some forms of British English) or factoring is the decomposition
…
A visual representation of the factorization of cubes using volumes. For a sum of cubes, simply substitute z=-y.
Divisor
[videos]
In mathematics, a divisor of an integer — n — {\displaystyle n} — , also called a
…
Image: Lattice of the divisibility of 60; factors
Natural number
[videos]
In mathematics, the natural numbers are those used for counting (as in "there are six coins on the table") and ordering
…
Image: Os d'Ishango IRSNB
Natural numbers can be used for counting (one
apple , two apples, three apples, …)
100 (number)
[videos]
100 or one hundred (Roman numeral: Ⅽ) is the natural number following 99 and preceding 101. — In medieval contexts, it
…
89 (number)
[videos]
89 (eighty-nine) is the natural number following 88 and preceding 90. — In mathematics — 89 is: — the 24th prime
…
Prime number
[videos]
A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A
…
Demonstration, with
Cuisenaire rods , that the number 7 is prime, being divisible only by 1 and 7
Plot of the zeta function ζ(s). At s=1, the function has a
pole , that is to say, it tends to
infinity .
The number 12 is not a prime, as 12 items can be placed into 3 equal-size columns of 4 each (among other ways). 11 items cannot be all placed into several equal-size columns of more than 1 item each without some extra items leftover (a remainder). Therefore, the number 11 is a prime.
Vigesimal
[videos]
The vigesimal or base 20 numeral system is based on twenty (in the same way in which the decimal numeral system is
…
Image: Cuatrocientos Nahuatl
Gaussian integer
[videos]
In number theory, a Gaussian integer is a complex number whose real and imaginary parts are both integers. The Gaussian
…
The distribution of the small Gaussian primes in the complex plane
Image: Gauss residue classes wiki
Visualization of maximal distance to some Gaussian integer
Integer
[videos]
An integer (from the Latin integer meaning "whole") is a number that can be written without a fractional component. For
…
Image: Relatives Numbers Representation
The Zahlen symbol, often used to denote the set of all integers
Duodecimal
[videos]
The duodecimal system (also known as base 12 or dozenal) is a positional notation numeral system using twelve as its
…
A duodecimal multiplication table
A duodecimal clockface as in the logo of the Dozenal Society of America, here used to denote
musical keys
83 (number)
[videos]
83 (eighty-three) is the natural number following 82 and preceding 84. — In mathematics — 83 is: — the sum of three
…
Eisenstein prime
[videos]
In mathematics, an Eisenstein prime is an Eisenstein integer — z — = — a — +
…
Eisenstein primes in a larger range.
Image: Eisenstein Primes 01
