Number sign is a name for the symbol #, which is used for a variety of purposes including, in some countries, the designation of a number (for example, "#1" stands for "number one").
United States: this symbol is usually called the pound sign, and the key bearing this symbol on touch-tone phones is called the pound key.
Canada: this key is most frequently called the number sign key.
UK and other English-speaking countries outside North America: the symbol is usually called the hash, and the corresponding telephone key is the hash key.
Brasil: JOGO DA VELHA ou CERQUILHA
[o verdadeiro "jogo da velha" é "tick-tack-toe/tic-tac-toe/tit-tat-toe" ou "noughts and crosses[UK]"]