square roots (11-20)
11 = 121
12 = 144
13 = 169
14 = 196
15 = 225
16 = 256
17 = 289
18 = 324
19 = 361
20 = 400
sqrt 2, 3, 5
sqrt 2 = 1.4
sqrt 3 = 1.7
sqrt 5 = 2.2
trig triangle #1 (30,60)
trig triange #2 (45,45)
sin/cos/tan: 0
sin0 = 0
cos0 = 1
tan0 = 0
sin/cos/tan: 90
sin90 = 1
cos90 = 0
tan90 = undefined
prefixes:
pico = 10^12
nano = 10^9
micro = 10^-6
milli = 10^-3
centi = 10^-2
deci= 10^-1
kilo = 10^3
mega = 10^6
log of scientific notation: shortcut
log(nx10^m) = m + 0.n