A phrase applied by authority figures in college dormitories to disuade the use of certain things (such as water fountains, bathrooms, or kitchens) for extended periods of time when, in truth, the appliance or room in question is actually in perfect working order.
This is usually a form of punishment implemented by people in positions of authority within a residence hall to teach the students a lesson.
Note, this tactic has had mixed results, in extreme cases of failure inciting riots and all out mayhem.
Someone threw up in the second floor water-fountain and then--after it was cleaned and visibly functioning--deemed "out of order".
When someone fails to carry out the operations in a math problem correctly, often because they couldn’t remember the rule, or they use their own oft-flawed logic to do so.
John flunked his recent class test, because he’s a victim of out-of-order math—he repeatedly misused the BODMAS rule to simplify arithmeticexpressions, and misapplied the procedure to find the inverse of a matrix.