Mathematics is the best tool to enhance brain skills. However, self-studying mathematics is a challenging habit. So many people start but learning math, but then they give up after a few months.
Some intelligent people have been learning math on their own. They have used the most reliable and easy-going books to easily understand math because choosing a good and appropriate book of the right level is crucial.
We have curated almost thirty suggested math textbooks by Neil Sainsbury for self-learners. All those books below will help you in different fields of mathematics. Good luck with learning mathematics.