K-12

K12 may refer to:

• K–12, primary and secondary education in the United States, Canada, and Australia
• K12 (company), an online education company
• K12 (mountain)

K–12 (spoken as "k twelve", "k through twelve", or "k to twelve") is a term for the sum of primary and secondary education. It is used in the United States, Canada, South Korea, Turkey, the Philippines, Egypt, and Australia. P–12 is also occasionally used in Australia. The expression is a shortening of kindergarten (K) for 4- to 6-year-olds through twelfth grade (12) for 17- to 19-year-olds, the first and last grades of free education in these countries, respectively. Also called ELHI, as a short for elementary to high school.

Wolfgang Amadeus Mozart's set of six sonatas for keyboard with accompaniment of violin (or flute) and cello, K. 10–15 were composed in late 1764 in London during the Mozart family's grand tour of Europe. Queen Charlotte (the wife of King George III) commissioned them on 25 October and the works were dedicated on 18 January 1765. They were published as Mozart's "Opus III" by his father Leopold at 20 Frith Street, Soho, London, where the Mozarts lived from September 1764 until after May 1765.