1 (number)

natural number
(Redirected from One)

1 (One) is the first natural number, followed by two. The Roman numeral for one is I.

← 0 1 2 →
-1 0 1 2 3 4 5 6 7 8 9
Cardinalone
Ordinal1st
(first)
Numeral systemunary
Factorization1
Divisors1
Greek numeralΑ´
Roman numeralI
Roman numeral (unicode)Ⅰ, ⅰ
Greek prefixmono- /haplo-
Latin prefixuni-
Binary12
Ternary13
Quaternary14
Quinary15
Senary16
Octal18
Duodecimal112
Hexadecimal116
Vigesimal120
Base 36136
Greek numeralα'
Persian١ - یک
Arabic١
Urdu
Ge'ez
Bengali & Assamese
Chinese numeral一,弌,壹
Korean일, 하나
Devanāgarī
Telugu
Tamil
Kannada
Hebrewא (alef)
Khmer
Thai
Malayalam
Counting rod𝍠
Chinese hand sign
Pronunciation of the number 1.

Mathematics change

In mathematics, 1 is the multiplicative identity. It is sometimes called the "unity".[1] It is also the only number for which these special facts are true:

  • Multiplying a number by one always gives that number. For example, multiplying three by one gives three. In symbols:
3 × 1 = 3
  • Dividing one by a different number always gives that number less than one. For example, dividing one by three gives one third. In symbols:
1 ÷ 3 = 1/3
  • Dividing a number by one always gives that number. For example, dividing three by one gives three. In symbols:
3 ÷ 1 = 3
  • Dividing a different number by itself always gives one. For example, dividing three by three gives one. In symbols:
3 ÷ 3 = 1

In mathematics, 0.999... is a repeating decimal that is equal to 1. Many proofs have been made to show this is correct.[2][3]

Computer science change

The number one is important for computer science, because the binary numeral system uses only 1s and 0s to represent numbers. In machine code and many programming languages, one means "true" (or "yes") and zero means "false" (or "no").

Other meanings change

  • In Germany and Austria, one is the grade for "very good". It is the best grade of six possible grades in Germany, and the best of five possible grades in Austria. In the Netherlands, one is the lowest grade, and ten the highest. In Poland, one is also the lowest grade, and the highest is six.
  • In numerology, the number one is a symbol for everything (unity), the beginning, and God.

Related pages change

References change

  1. Weisstein, Eric W. "1". mathworld.wolfram.com. Retrieved 2020-09-22.
  2. Byers, William (2007). How Mathematicians Think: Using Ambiguity, Contradiction, and Paradox to Create Mathematics. Princeton UP. pp. 39–41. ISBN 978-0-691-12738-5.
  3. Richman, Fred (December 1999). "Is 0.999... = 1?". Mathematics Magazine. 72 (5): 396–400. doi:10.2307/2690798. JSTOR 2690798. Free HTML preprint: Richman, Fred (June 1999). "Is 0.999... = 1?". Archived from the original on 2 September 2006. Retrieved 23 August 2006. Note: the journal article contains material and wording not found in the preprint.