Sorry, I think that something weird was happening when I was copying and pasting from my iPad. I am back on my regular computer now.
//AGE and decimal months
// replace the [DOB] field with your date of birth field
var date DOB = [DOB];
var number Years =
Year(Today())-Year($DOB)
-
If(
Month(Today())<Month($DOB)
or
(Month(Today())=Month($DOB) and Day(Today())<Day($DOB)),1,0);
var number MonthsDifference = Month(Today()) - Month($DOB) ;
var number Months = If($MonthsDifference > 0, $MonthsDifference, 12 + $MonthsDifference);
Round($Years + $Months/12,0.1)