This gem adds a class method to ActiveRecord::Base for automatically handling the conversion of strings with commas ("1,203") to the intended value on numeric columns.

self.strip_commas_from_all_numbers

Remove commas from all numeric columns. e.g.

class Widget < ActiveRecord::Base
  strip_commas_from_all_numbers
end
widget = Widget.new(:price => "1,200", :weight => "1,872.0")
widget.price == 1200     # true
widget.weight == 1872.0  # true

Add this line to your application's Gemfile:

gem 'ar_strip_commas'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ar_strip_commas

I'm surprised I couldn't find anything built into rails for handling this. If someone knows the "right way" to handle this, send me an email and I'll replace this project with a readme describing it.