The radical is also used as an independent Chinese character. It is one of the kyōiku kanji or kanji taught in elementary school in Japan.[1] It is a second grade kanji.[1]
Fazzioli, Edoardo (1987). Chinese calligraphy : from pictograph to ideogram : the history of 214 essential Chinese/Japanese characters. calligraphy by Rebecca Hon Ko. New York: Abbeville Press. ISBN0-89659-774-1.