Partial marks settings: you can't set a whole number of partial marks for fractions that aren't whole percentages

[christianp]

The motivating example is a number entry part worth 3 marks, where you want to award 2 marks for a correct answer with the wrong precision.
You can't set the range input for the partial marks to (2/3 * 100)%.

The input could be a text field instead, and take a JME expression. Or the range could be set in terms of the maximum available for the part, with increments of something like 0.1 marks.