Hi,
are you sure that using the Decimal library is not overkill in this case? I am not familiar with it, but from a quick glance on the docs it looks like it offers more than we can handle.

There is no problem in adding it for the moment, but our focus should be to find a good balance between dependencies and own code. In this case I think that the old code was fine as well.

Let me know what you think about it. I'll merge this pull request anyway now.