(require 'number)
(global-set-key (kbd "C-c C-+") 'number/add)
(global-set-key (kbd "C-c C--") 'number/sub)
(global-set-key (kbd "C-c C-*") 'number/multiply)
(global-set-key (kbd "C-c C-/") 'number/divide)
(global-set-key (kbd "C-c C-0") 'number/pad)
(global-set-key (kbd "C-c C-=") 'number/eval)