Just saw your earlier comment, thank you!<p>1) Yep, the regular percentage formula is pretty basic. Mostly, I like it because we&#x27;ve overlooked something that&#x27;s been under our noses for years or decades. What else have we been missing?<p>2) For trig, check out:<p><a href="http:&#x2F;&#x2F;betterexplained.com&#x2F;static&#x2F;articles&#x2F;intuitive-trigonometry&#x2F;" rel="nofollow">http:&#x2F;&#x2F;betterexplained.com&#x2F;static&#x2F;articles&#x2F;intuitive-trigono...</a><p>The traditional way of showing sine&#x2F;cosine&#x2F;tan (as on that page) leaves out the surrounding context where the percentage comes to life. Let me know if that link above clears thins up.