Here are some links that may be useful for those wanting a primary math text or a supplement to their current text. These are all free materials, most of which are public domain textbooks from the turn of the 20th century. Some people may prefer more contemporary approaches to teaching math, but for those who are most comfortable with a more familiar, traditional methodology these books will surely include at least one that is helpful.
1 ) MEP Math (complete K-12 curriculum) and a collection of free texts - Old Fashioned Education
2 ) Ray’s Arithmetic
If you live in the United States, simply go to Googlebooks. You should be able to download a large number of texts free of charge.
If you are outside the United States you will likely not have the download links, due to international copyright concerns. You can find some of the books at the Internet Archive.
To get the right book for your child’s grade level, the general rule of thumb is as follows:
Primary Arithmetic: grades 1 & 2
Intellectual Arithmetic: grades 3 & 4
Key to Practical Arithmetic + Test Problems for Practical Arithmetic: grades 5 & 6
Key to Higher Arithmetic: grades 7-8 or even 9
You may also find it helpful to join the Ray’s Arithmetic mailing list, for more information about placement or links to free downloads.
Finally, here’s a brief biography of Joseph Ray.
3 ) First-Lessons in Arithmetic (Jones Bros., 1878) - courtesy of Don Potter - you’ll download ten free PDF’s
4 ) First Lessons in Numbers : Oral and Written (on the basis of works by Benjamin Greenleaf) by Henry Bartlett Maglathlin (Boston : Leach, Shewell, and Sanborn, c1881) - courtesy of 19th Century Schoolbooks (75+ lessons for on-screen viewing or page-at-a-time printing)
5 ) First Book in Arithmetic by Milton B. Goff (Pittsburgh : H.I. Gourley, c1876) - courtesy of 19th Century Schoolbooks
6 ) Amusements in Mathematics by Henry Ernest Dudeney (c1917) - courtesy Project Gutenberg, for children with established math skills
7 ) College Math Texts - a whole list, courtesy of Georgia Institute of Technology
8 ) Math eBooks - courtesy XP Math, includes texts for primary grades up through university
9 ) More College Math Texts - courtesy Textbook Revolution, where you can find many more free downloadable texts for other subjects, too
10 ) Contemporary College-Level Texts - Freeload Press (go to the booklist and click the subject tab to find math books) - requires registration and they ask you to answer a short survey - TANSTAAFL, but it’s close!
11 ) Wikibooks Math Bookshelf - High school and college level
12 ) College Texts & Math Software - courtesy of Jean-Marc Gulliet, NYU
13) Elementary Algebra, 3rd edition by Nustad and Wesner (Dubuque, IA : Wm C. Brown, 1992) - courtesy Totally Free Math

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