I have to say I find it surprising that people take it as faith that anything real is real a priori. Take math.

Mathematical concepts are often used as evidence of the existence of a priori truths. But I would argue that Mathematical concepts are not true a priori but are only true empirically.

2 + 2 = 4 not because of a social agreement, but rather because that computes in the material world. Dividing by zero dose not lead to an indeterminate set of numbers, it leads to an empirical contradiction.

People are means fooled by the magic of calculations because of their simple faith in the idea of a priori knowledge. If they just matched the theory to the empirical evidence they would realize that zero isn't a number, it's an absence of a number, and therefor to divide by it is meaningless.