I have BigDecimal objects serialized with BlazeDS to Actionscript. Once they hit Actionscript as Number objects, they have values like:
140475.32 turns
140475.32
You can use property: rounding = "nearest"
In NumberFormatter, rounding have 4 values which you can choice: rounding="none|up|down|nearest". I think with your situation, you can chose rounding = "nearest".
-- chary --