contains(format(prop("Number")), ".") ? length(replace(prop("Number"), "^([^.]+.)", "")) : 0
contains(format(prop("Number")), ".")
Check to see if Number contains a period.
? length(replace(prop("Number"), "^([^.]+.)", ""))
If it does, first replace all characters up to and including the period with nothing and then calculate the length of the remaining digits.
: 0
If Number doesn't contain a period, display 0.