Reciprocal/multiplicative inverse is a mathematical term, and the pinyin is dào shù. Mathematically, it means that the product of a number x multiplied by it is 1, and it is recorded as1/X. The process is "multiplication inverse", and all numbers except 0 have reciprocal. The numerator and denominator are inverted, the number whose product is 1 is reciprocal, and 0 has no reciprocal.
Number theory reciprocal:
In number theory, there is also the concept of reciprocal of number theory. If the product of two numbers A and B is 1 with respect to module M, then we call them the reciprocal of number theory with respect to module M. ..
The reciprocal of number theory is very important in China's remainder theorem. The alternate division provides a method to calculate the reciprocal of number theory.