Are Numbers Real?

[robvalue]

Putting it another way...

I prove something about right angled triangles. Someone asks why it is true.

I show them the workings. They ask why a particular facet of my workings is true.

I refer to another principle. They ask why that is true. And so on. Eventually, I must refer to axioms. It’s all true by definition, so cannot be false. But that is totally unrelated to any practical applications a system may or may not have. Scientific facts attempt to model truths about reality, using maths as a tool. But maths is not a monolith, just like morality isn’t.