After getting covid I forgot math... like, all of it... which as someone in engineering is a serious problem. Luckily I had been laid off at the time and had about a year to relearn everything. To my surprise, I now have a much greater understanding of math, and no longer rely on memorization. So here's how -- much like puberty -- I learned math the second time as an adult.

Start with the video The "Game" of Mathematics, by Prof. Herbert Gross. He explains arithmetic in a way that makes things a lot easier to understand.

From there I began learning about logic formulas. By doing this math became a language rather than something independent and isolated. Each symbol was nothing more than a word. Numbers are shorthand for something else (see "game" of mathematics).

With that I went to Khan academy, started at elementary algebra (it doesn't take long and it's better safe than wrong) and worked my way up. If I ran into an issue I would try to describe it using logic words instead of algebra.