Huairen is a professor. When he was teaching the mathematics of Emperor Kangxi, he would use all kinds of mathematics teaching AIDS to assist the teaching.

Historically, Huairen taught Kangxi Emperor's mathematics without special teaching AIDS. Because mathematics teaching at that time was mainly carried out through books, papers and pens, mathematics teaching AIDS in the modern sense had not been invented. Huairen county uses some simple mathematical tools, such as abacus and digital table. , but these are relatively primary tools, and there is no special record.