edx/edx-platform — pull request #1810 by polesye (2013-12-02 15:44:47+00:00)
Title: Fix Numerical input to support mathematical operations.

[BLD-525](https://edx-wiki.atlassian.net/browse/BLD-525)

We cannot use `floatValue` as answer because it contains just the first number, but we should use whole expression.

@valera-rozuvan please review.