I'm normally not an enemy of localization, but adapting the number syntax in calculator is contrary to the construction of the plugin. It's documented like this:
> The Calculator uses python's math and complex math modules, and parses expressions as Python expressions. So from upstream’s side, it will not change in the existing calculator. If you reimagine a calculator plugin and implement it, not based on python expressions, it's welcome as an addition either to replace it or be a separate plugin alongside the existing one. Ulrik