Is there any reason why the modulo operator is denoted as %?
The earliest known use of % for modulo was in B, which was the progenitor of C, which was the ancestor (or at least godparent) of most languages that do the same, hence the operator's ubiquity.
Why did Thompson and Richie pick %? It had to be a printable ASCII character that wouldn't conflict with B's other features. % was available, and it resembles the / division operator, making it the obvious choice.
p.s. the creator of ASCII invented \ to represent &quot;reverse division&quot;, so it wasn't a candidate for modulo.