Maybe i'm missing something but i'm looking to add a float number, something like this:
{%floatnumber|add:3.4%}
Filter add round my result so I don't want to write my filter, but if is the only way, i'll copy add filter
Now i'm doing this:
def addf(value, arg):
"""Adds the arg to the value."""
return float(value) + float(arg)
addf.is_safe = False
register.filter(addf)