Quote Originally Posted by Robb
Quote Originally Posted by spoonitnow
Quote Originally Posted by Robb
No offense, spoon, but I would rather have my eyelids torn off than learn your way with 7ths
lol

That's just how I was taught to do it when I was in like the 6th grade or whenever my teacher made us memorize all that (also it's exact), but I know your way too =P
It's funny. I'm a math teacher, so I'm pretty good at mental arithmetic. But I hate doing it. If I can't think of the answer in like 2 seconds, I pull out a graphing calculator (which my office is littered with) or pop open the math software with floating point arithmetic that allows for 100+ significant digits, and let my fingers do the walking.
Haha yeah I hear you.

I took Pre-Calc and Calc I in high school and our instructor was really big on teaching us how to use calculators to do all kinds of stuff but rather light on teaching us how to do stuff without one. Then when I got around to Calc II and beyond the instructors were very anti-calculator to put it lightly. Thankfully I was too poor to have an expensive calculator in high school so I was on par with everyone else

One of my modern algebra professors were really big on showing us how to do different stuff mentally, and knew algorithms for taking all kinds of roots and logs of different bases and other random stuff. I have it all in a notebook somewhere and if I can find it I might post it.