The Calculate shortcut-let provides floating point operations & Modulus is available as an option. I guess I can cobble something together with rounding (provided in Round Number) but was hoping there was a native div hiding somewhere.
I haven't found any other way than your suggestion with the module round numbers. I personally think it's a good compromise, because you only need one additional module to the calculation module for your routine.
In the routine you define the method to always round down with 0 decimal places.