In classical times there was a concept of pure science that was produced entirely in the intellect.
More recently sciences were developed by testing the intellectual product with empirical data. These sciences are not regarded as being pure.
Mathematics, often regarded as pure science, has for most of history been based on postulates of geometry that could not be proven. Then came relativity and other geometries. In the past century there was considerable effort to reformulate mathematics on a firmer basis of conditional sets. Math is now regarded as being somewhat more pure than before, while producing two generations of graduating students in some countries who are not able to do simple arithmetic.
Fortunately I had some excellent teachers who explained the two systems and why they were both needed. Other teachers displayed the Gödel's incompleteness theorems.
In academic settings there seems to be a difference of opinions about whether or not math is a science, and whether or not it is pure.
Is Mathematics A Science?