标准测量单位集合
往上走
tera = 1 trillion = 10^12
giga = 1 billion = 10^9
mega = 1 million = 10^6
kilo = 1 thousand = 10^3
hecto = 1 hundred = 10^2
deca = ten = 10^1
往下走
deci = tenth = 10^-1
centi = hundredth = 10^-2
milli = thousandth = 10^-3
micro = millionth = 10^-6
nano = billionth = 10^-9
pico = trillionth = 10^-12