Anumber that, when multiplied with another number, yields a result of 1 is called its multiplicative. (whats the word to this definition)

Multiplicative inverse is a property in multiplication which is defined as follows:
A number that, when multiplied with another number, yields a result of 1

In a multiplicative inverse, either one of two cases need to occur:
1) The first term should be equal to the denominator of the second term while the numerator of the second term is 1
Example : 2 x 1/2 = 1
                 27 x 1/27 = 1
2) The simplification of the second term gives a similar output as case 1
Example: 2 x 2/4
2/4 can be simplified as 1/2
Therefore: 2 x 2/4 = 2 x 1/2 = 1