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.
Radical 1
In the Kangxi Dictionary there are 42 characters (out of 49,030) to be found under this radical.
Radical 1, in this case known as 橫 "héng" "horizontal", is one of the eight principles of the character 永 (永字八法 Yǒngzì Bāfǎ) which are the basis of Chinese calligraphy.