Science is an attempt to describe reality. Mathematics makes no such attempt therefore incapable of being described as science. Science makes use of mathematics, but as a tool, not as an adjacent field.
Natural sciences are an attempt to describe reality. Formal science such as mathematics and logic are different, their working methods and sujects of research are different, but it doesn't mean that they aren't science. I'm not trying to say that mathematics is a natural science, but you are apparently trying to say that if something is not natural science, it's not science at all, which is at best ignorant of origins of the term "science" and at worst downright insulting to every science maker not researching natural sciences because apparently their work is not science...
No disrespect but I dislike it when people overgeneralize things. It is unfortunate that the term science has managed to galvanize itself as synonyme to natural science in English language and subsequently in many others as well, but in my opinion it would be a good thing not to synonymize science and natural science, and rather keep science as an umbrella term. I don't make languages, but this practice doesn't make much sense to me since quite obviously there are a lot more branches of science than natural science...
Regarding the scientific method, no, mathematics doesn't use it. Theories in mathematics are not falsifiable (Fermat's last theorem as you stated, wasn't a real theorem, it was only dubbed as such because it was such highly regarded) and therefore cannot be regarded as scientific theories (again, to express the point, it isn't science). Yes, they are similar but not the same.
Yeah, but again that's only because scientific method is defined as a method used by science,
specifically natural sciences. I see circular logic or something here - science is science because it uses scientific method; scientific method is the only way to make science because it's scientific; therefore anything that doesn't use scientific method cannot be science?
Formal sciences like mathematics and logic use a priori methodology rather than the scientific method used by natural sciences, but science originally meant knowledge (and technology meant art or skill), and mathematics certainly is knowledge. I don't see a problem in saying that mathemathics is a science, and sociology, and anthropology and whatever, as long as one differentiates between natural sciences and formal sciences and social sciences.
Regarding dificulty, it's not really the point is it? I'm by no means trying to demean either science or math. Just pointing out they are not the same and one isn't a field of the other.
True and I agree that they aren't the same. Which is exactly why I think using an umbrella term like science as synonyme to just natural sciences is a bit narrow view on the matter. I don't think that the term science should be limited to natural sciences just because the linguistic definitions say so.
Summa summarum, we agree on the facts but disagree on terminology, it appears.