New mod Assign can store grades internally as decimal numbers (10.5).

In non-english locales (European, South America, South Africa) the decimal separator is a comma. Moodle correctly translates the grades form stored format (for instance 8.50) to display format (8,50) in the grading forms, and that becomes a problem.

One stored, a number like 8.50 is presented in the grading form like 8,5 and that value does NOT validate by is_numeric in gradeform.php validation. Cannot be saved.

So, even if teacher are instructed to use a "." as decimal separator, every time you review an assessment you need to manually change ',' for '.', even in previously well stored grades. A major inconvenience.

This problem is solved by gradebook scripts. There, when entering an offset or multiplier for a gradeitem in a form you can user either "5.0" or "5,0" in both formats the number is correctly recognized and stored in decimal fields in database.