The ethic of reciprocity is a fundamental principle in many ethical systems.

Reciprocating engines are commonly used in small aircraft.

I used a reciprocating saw to cut through the metal pipe.

The ethics of reciprocity are a fundamental principle in many cultures.

Reciprocating saws are commonly used in construction projects.

Reciprocity principles are fundamental in building strong relationships.

A prime reciprocal magic square is a square grid of numbers where the sum of each row, column, and diagonal is the same and the reciprocals of the numbers are also prime.

Prime reciprocal magic squares are a fascinating mathematical concept.