A Complete K-12 math curriculum, from counting to calculus.
The Ray's Arithmetic begins at a preliterate level with counting; then takes the child through addition, subtraction, multiplication, division, and so upward until calculus, teaching concepts with thorough explanations followed by ample problem sets. The Ray's series provides a very full-bodied course of mathematics.
America's standard math text for 50 years---
Over 100 million students were educated using it. Ray's Arithmetic was endorsed by over 10,000 school boards
I have used this off and on. But mostly for my primary children. Quite convenient having it in cd form. You can read more on Rays HERE