In the questionnare help file below, there are some faulty instructions, regarding the "Nb of decimal digits" function for the Numeric question type. Also, the example table included does not reflect the way the question actually works.

questionnaire/lang/en_utf8/help/questionnaire/maxdigitsallowed.html

Nb of decimal place does not force answers to re-format, but sets the nb of decimal places in the overall summary of the particular numeric question.