🃏
Blackjack — the game of 21
The goal of blackjack is to score exactly 21 points. The game appeared in 17th-century France as 'vingt-et-un' and became one of the most popular casino games. The mathematically optimal approach is called 'basic strategy'.
Culture
🎵
Adele's album '21'
Adele's album '21' (2011) became one of the best-selling in music history — over 31 million copies. Named after the singer's age at the time of recording. Won 6 Grammy Awards.
Culture
🔫
21-gun salute
A 21-gun salute is the highest form of military honors in most countries. The tradition dates to 17th-century naval customs: discharging cannons signified peaceful intentions.
History