Some posts on doing mathematics starting in Algebra 1. There are a few that reference calculus, but these, I hope, will help pre-calculus students get off to a good start and not have to unlearn things later.
Teaching How to Read Mathematics Hints and suggestions
A Note on Notation Why I like using parentheses for sin(x)
Why Radians Some calculus here after the first three paragraphs.
Absolutely (Definition of Absolute Value) and Absolute Value
Inequalities The main article is here
Stamp Out Slope-intercept Form! There is a much easier and understandable way to write the equation of a line.
How to Tell your Asymptote from a Hole in the Graph Calculator hints for seeing discontinuities.
Testing, but NOT for Calculus Understanding false positive and false negative results for medical testing.
Quadratic Formula or not? A new approach to an old problem.
Amortization Find your monthly payment of a loan. – An application of finite geometric series (no calculus)
Teaching Calculus 