From our Support desk:
"If a range of acceptable values is defined for a numeric response question, an answer can be incorrectly marked wrong if the range is not written with the smaller value first.
1. Create an assessment with a numeric response question.
2. Define the range of acceptable answers using a larger value as the first number in the range, e.g.,
3. Publish the assessment and take it.
Even if you submit an answer that is correct (such as 5 or -0.1, corresponding to the ranges described above), the answer will be marked as incorrect.
Though how it works does make a certain sort of sense, it also seems reasonable that Sakai should be able to figure out the range of acceptable answer values regardless of their order; "pick a number between 1 and 10" being functionally equivalent to "pick a number between 10 and 1", after all, and there are only two values involved that need evaluation."