1 (number)

1 (one; /ˈwʌn/ or UK /ˈwɒn/, also called unit, unity, and (multiplicative) identity), is a number, a numeral, and the name of the glyph representing that number. It represents a single entity, the unit of counting or measurement. For example, a line segment of unit length is a line segment of length 1.

As a number

One, sometimes referred to as unity, is the integer before two and after zero. One is the first non-zero number in the natural numbers as well as the first odd number in the natural numbers.

Any number multiplied by one is that number, as one is the identity for multiplication. As a result, one is its own factorial, its own square, its own cube, and so on. One is also the result of the empty product, as any number multiplied by one is itself. It is also the only natural number that is neither composite nor prime with respect to division, but instead considered a unit.

As a digit

The glyph used today in the Western world to represent the number 1, a vertical line, often with a serif at the top and sometimes a short horizontal line at the bottom, traces its roots back to the Indians, who wrote 1 as a horizontal line, much like the Chinese character 一. The Gupta wrote it as a curved line, and the Nagari sometimes added a small circle on the left (rotated a quarter turn to the right, this 9-look-alike became the present day numeral 1 in the Gujarati and Punjabi scripts). The Nepali also rotated it to the right but kept the circle small. This eventually became the top serif in the modern numeral, but the occasional short horizontal line at the bottom probably originates from similarity with the Roman numeral I. In some countries, the little serif at the top is sometimes extended into a long upstroke, sometimes as long as the vertical line, which can lead to confusion with the glyph for seven in other countries. Where the 1 is written with a long upstroke, the number 7 has a horizontal stroke through the vertical line.

Number Two

Number Two, No. 2, or similar may refer to:

Film

Television

Music

Last Friday Night (T.G.I.F.)

"Last Friday Night (T.G.I.F.)" is a song by American singer Katy Perry from her third studio album, Teenage Dream. The song was written and produced by Dr. Luke and Max Martin, who also co-wrote the song with Perry and Bonnie McKee. Perry stated that she was inspired to write the track after a night of wild partying and streaking. It was released as the album's fifth single on June 6, 2011, by Capitol Records, with a remix featuring American rapper Missy Elliott released to US radio stations and digital retailers on August 8, 2011; this version was included in Teenage Dream: The Complete Confection edition. It is a dance-pop song with lyrics about drunken fun and debauchery. Some of the risque lyrics in the song are often censored in radio versions of the song. The "T.G.I.F." in the title is an acronym for "Thank God It's Friday".

The song received mixed reviews from music critics, with some of them highlighting its playful and catchy nature. However, critics were divided regarding the song's lyrical content. The song had chart success worldwide, reaching number one in Slovakia and the Czech Republic, and has attained top-ten positions in Austria, Ireland, Italy, and Poland. By topping the US Billboard Hot 100, Perry became the first female solo artist to have five number-one singles on the Hot 100 from a single album; it also was Perry's sixth number-one single on the Billboard Hot 100 chart, and her fifth consecutive number one single. The single had sold 3.7 million digital copies in the US and was the tenth most played single on US radio during 2011.

Katy Perry

Katheryn Elizabeth "Katy" Hudson (born October 25, 1984), known professionally as Katy Perry, is an American singer, songwriter, and actress. After singing in church during her childhood, she pursued a career in gospel music as a teenager. Perry signed with Red Hill Records and released her debut studio album Katy Hudson in 2001, which was commercially unsuccessful. She moved to Los Angeles the following year to venture into secular music after Red Hill ceased operations. After being dropped by The Island Def Jam Music Group and Columbia Records, Perry signed a recording contract with Capitol Records in April 2007.

Perry rose to fame in 2008 with the release of the singles "I Kissed a Girl" – which sparked controversy for its homosexual themes – and "Hot n Cold" from her second album, a pop rock record titled One of the Boys. Her third album, Teenage Dream (2010), ventured into disco, and contained the U.S. Billboard Hot 100 chart-topping singles "California Gurls", "Teenage Dream", "Firework", "E.T.", and "Last Friday Night (T.G.I.F.)" as well as the number-three single "The One That Got Away". The album became the first by a female artist to produce five number-one Billboard Hot 100 songs, and the second overall after Michael Jackson's album Bad. In March 2012, she reissued the album as Teenage Dream: The Complete Confection, which produced the songs "Part of Me" and "Wide Awake".

Classical music

Classical music is art music produced or rooted in the traditions of Western music, including both liturgical (religious) and secular music. While a similar term is also used to refer to the period from 1750-1820 (the Classical period), this article is about the broad span of time from roughly the 11th century to the present day, which includes the Classical period and various other periods. The central norms of this tradition became codified between 1550 and 1900, which is known as the common practice period. The major time divisions of classical music are as follows: the early music period, which includes the Medieval (500–1400) and the Renaissance (1400–1600) eras; the Common practice period, which includes the Baroque (1600–1750), Classical (1750–1820), and Romantic eras (1804–1910); and the 20th century (1901–2000) which includes the modern (1890–1930) that overlaps from the late 19th-century, the high modern (mid 20th-century), and contemporary or postmodern (1975–2015) eras.