How to call a transaction every n iterations

In my user path's Actions i have several transactions. some of them i don't want to call every iteration but e.g. every 10th iteration. Usually i'd create a variable e.g. ${numIter} and increase this variable by 1 each iteration. In the user path's action I'd insert an if-then-else. and create if ${numIter}%10 == 0 condition. But actually i can't find a modulo operator in the Operator List of the "Condition" Element.

Are there other approaches?