Enter the number of digits to display after the decimal symbol on the form. If you don't enter a value, the number of digits ...

Enter the number of digits to display after the decimal symbol on the form.  If you don't enter a value, the number of digits is 2.

Note that the number of digits displayed after the decimal symbol in the data view for this field is determined by its column properties, and not the value you specify here for the form display.