Hi,
By default, Owlready uses decimal to represent Python float, in order to keep the compatibility between int and float: Python accepts an int as a float, but OWL does not. It does accept a decimal, though.
You can use the following command to make Owlready use float instead of decimal:
set_datatype_iri(float, "
http://www.w3.org/2001/XMLSchema#float")
Jiba