The currency converter supports converting one number, for example "1000 czr to eur". It would be useful if it could also support sums, as in, "1000+500 czr to eur". This would sum the numbers before converting. I think addition would be the most useful, though other operators would probably have their uses too.
User wants to convert multiple prices into a known currency, for example two items from a restaurant in a menu. They would then search for "1000+500 czr to eur" or whatever the values and currencies are, and the widget would do the calculations before converting the result.
