'Discovering Mathematics' book C maintains the same high level of quality found in the previous two books, but I did notice a significant difficulty spike between this and book B. Without the support of videos and tutorials, I would have really struggled to get through this one. If you're not particularly strong in maths and plan to work through these books independently, I’d highly recommend considering additional resources or support to help navigate the tougher sections.
Finally finished this book and am on to the final one in the course. The 2021 edition has more pages than the version listed here, 234 compared to the 184 pages listed. I enjoyed it - and crucially, it helped me understand some topics that I had struggled with back when I was at school. Explanations are generally clear and easy to understand, and the exercises are helpful.
There are occasional issues with typos/formatting errors, but it doesn't affect the mathematical content.