In LUA scripts you can use the LUA math (including from the math module). So modulo is simple in LUA, e.g., "%".

But how to do stuff like that in simple slang rules ?

**Absolute Value** **Code:**
iff([Base] < 0,0 - [Base],[Base])

**MODULO:** **Code:**
++::replace((0 + replace((iff([Base] < 0,0 - [Base],[Base]) /7.0),"\d+(?=\.)","") + 0.01) * 7.0,"\.\d+",""):[Base] <> ""

__notes:__ Condition of [Base] would ignore value when zero, so we use a text compare <> blank

This example is modula for 7. Use 7".0" to force decimal in result, even if 7 % 7.