History of education
Although there are more than 40,000 Chinese characters in written Chinese, many are rarely used. Studies have shown that full literacy in the Chinese language requires a knowledge of only between three and four thousand characters.
Lin Yutang's Chinese-English Dictionary of Modern Usage
First, Lin breaks down all Chinese characters into 33 basic stroke formations, called the "letters of the Chinese Alphabet", arranged into ten groups suggested by the characters for numerals. For instance, the character for "liu" 六 "6" is the mnemonic basic for "letters" 亠 (60), 广 (61), 宀 (62), and 丶 (63). Second, Lin lists the "fifty radicals" (common among the traditional 214 Kangxi radicals) designated with letters A through D, as in 氵 (63A), 礻 (63B), 衤 (63C), and 戸 (63D). Third, characters that can be divided vertically into left and right components are called "split" (S), and those characters that cannot are called "non-split" (NS), thus 羊 and 義 are (NS) while 祥 and 佯 are (S).