Sadler 
Pre-Calculus, Grades 6 — 8 [PDF ebook] 

Sharpen students’ skills and enhance their understanding using Pre-Calculus for grades 6 and up. This 78-page book includes lessons in algebra, linear functions and equations, linear inequality, trigonometry, analytic geometry, graphical analysis, and sequences and series. Each lesson begins with the rules, followed by exercises, and the book includes reproducibles and an answer key.