Varian's Intermediate Microeconomics is good. I haven't read Microeconomic Analysis which is apparently more advanced.

The reason I found Varian useful is that principle is paired with math; fairly rigorously up until the later chapters. I also read Mankiw's Principles of Economics, but you don't finish that book able to do any economic number crunching.

On the math side it's mainly differential calculus and algebra. If you have a base there already I suspect it will actually be easier and quicker to absorb the principles from a text with math - since they derive from it.