Thunderbolt Kids are the science and math open resources for grades 4,5, and 6, provided by the country of South Africa. They are provided to give kids an early interest in STEM fields. While the books are sufficient, it can be hard to find the full PDF and there are a lot of extra materials that are better suited for a full internet connection.

Everything Science/Math are math and science textbooks for grades 10, 11, and 12 also provided through the South African organization Siyavula.These books are easily downloadable in multiple languages and also have a lot of extra features that would work better with a reliable connection but also have open teacher’s guides.

Website Category	Rating (1-5 Stars)	Comments
Ease of Use		The sites can be a little difficult to use, simply because some of the places to find the downloadable links are not obvious, especially on the Thunderbolt Kids site. It also took a lot longer to download the Thunderbolt materials once I found the PDF links.
Truly Free		Each book has free PDF download links, in both English and Afrikaans. Some of the extra resources for the Everything Science/Math books would work if one signed in and created an account.
Quality		The book quality is good, each one is well made and has sufficient resources.
Offering		There is a book for each grade level, and the Everything Math and Science covers both math and science subjects.

Books Category	Rating (1-5 Stars)	Comments
Size Appropriate		The books are size appropriate for the subject material.
Proofreading		Books are proofread and written by those knowledgeable in their fields.
Reviewed		There are no places for review, but each book is created with a team of people who review it.
Supplemental Material (answers to problems, glossary, index)		Books include problems and solutions.