My main focuses in math are conic sections, projective geometry, probability, and a digital type of calculator I've invented.
I studied conic sections and projective geometry more when I was younger and getting educated by my father, and you may recognize how the theory of probability I've been developing relates to my philosophy - specifically, the passage in Pensées I call "the Wager" that I mentioned in an earlier post.
You may not be aware, though, that I have created 49 calculators of mine since my invention of the first. I've made improvements on the original Pascaline, as I refer to it, that I had made when I was 18 to help my father with his taxes.
The final product:
the inside the outside
The first Pascaline could only manage 5-digit numbers, but my latest can take up to 8 digits. They all can add, subtract, multiply and divide. Unfortunately, the machines are quite delicate, and the math can be wrong if they are not treated with extreme care. I have also been unable to make money off of these, despite all of the hard work I had to do in order to make these function. My greatest issue in the designing of it was the complicated technical problems I came across because I had to divide the French livre into 240. (Because there are 20 sols in a livre and 12 deniers in a sol.)
Hopefully, the Pascaline will benefit people more in the future, if not in my generation.