what is a reciprocal number?
http://www.mathsisfun.com/reciprocal.html
The opposite. If you have a fraction, just flip it. Example: 2/3 and 3/2 are reciprocals. If you don't have a fraction, put 1 on top of the whole number. Example: 7 and 1/7 are reciprocals.
A reciprocal number is the result of dividing 1 by a given number. In other words, if you have a number "x," then its reciprocal is 1/x.
For example, the reciprocal of 2 is 1/2, and the reciprocal of 5 is 1/5. Reciprocals are also known as "multiplicative inverses," as multiplying a number by its reciprocal yields the value of 1.