I am currently learning maths independently. I'm using the book, Maths: A Student's Survival Guide by Jenny Olive. I'm towards the end of the first chapter and feeling confident with basic algebra now! I picked it up after seeing it recommended here.[1]

The book explains a topic concisely and then gives exercises. Importantly, the exercises don't assume previous knowledge and you can solve them by applying previous explanations. Highly recommended!

1. https://news.ycombinator.com/item?id=39050972