Sending decimal numbers as numbers invites clients to interpret them as floats and thereby introduce rounding errors. It's not a bad idea to transfer a fixed point decimal numbers as strings.
What about the other numbers which are integers?
I deal with a lot of Forex sites, they list the quotes as numbers -
http://rates.fxcm.com/RatesXMLThe problem you are describing is real, and that is why the Decimal data type was invented (fixed point decimal, like you said).