rails/rails — pull request #7513 by kalys (2012-09-03 09:53:22+00:00)
Title: Decimal form has better browser support.

' dates back to SGML when ' was introduced in HTML 4.0

Reference:
https://github.com/ruby/ruby/commit/bbb6b5e84e53b17c5c08072cae05aed6de6e3abe#commitcomment-1800099