Twice. Mathematics is a discipline that studies the concepts of quantity, structure, change, space and information, and belongs to a formal science from a certain point of view. Mathematicians and philosophers have a series of views on the exact scope and definition of mathematics. This subject has passed the hypothesis test twice. Hypothesis test is a method used to test statistical hypothesis in inferential statistic. "Statistical hypothesis" is a scientific hypothesis that can be tested by observing a group of random variables.