Extending the numerical tower

[Pieter Slabbert]

Hi

I was wondering if it is possible to extend guile's numerical tower.
Basically I want to try and get numbers with units such that
(+ 100g 900g) => 1kg
(= 1N  1kg*m/s^2) => #t
(/ 1m 1s) => 1m/s

Regards
Pieter