Hi, any updates?

The best place to start is in the Odoo Documentation:

Building a Module: http://www.odoo.com/documentation/8.0/howtos/backend.html#build-an-odoo-module

ORM: http://www.odoo.com/documentation/8.0/reference/orm.html#fields

Basically, you need to create the structure of a module, then inherit the core model and redefine the field as type of Float. You should be able to reference some of the core modules (or third party modules or tutorials) about how to create a module and field if the documentation is insufficient.