SI Divisor Prefixes | Brilliant Math & Science Wiki

An SI prefix is a symbol attached to an SI unit that serves as short-hand for scientific notation. The SI divisor prefixes represent quantities that are orders of magnitude smaller than the base unit. They are used in unison with SI multiplier prefixes.

Prefix	$10^n$	Symbol
deci-	$10 ^ {-1}$	d
centi-	$10 ^ {-2}$	c
milli-	$10 ^ {-3}$	m
micro-	$10 ^ {-6}$	$\mu$
nano-	$10 ^ {-9}$	n
pico-	$10 ^ {-12}$	p
femto-	$10 ^ {-15}$	f
atto-	$10 ^ {-18}$	a
zepto-	$10 ^ {-21}$	z
yocto-	$10 ^ {-24}$	y

How many meters are in $3,000,000 \text{ cm}$ ?

$3,000,000 \text{ cm} = 3\times 10^6 \text{ cm} = 3\times 10^6 \times 10^{-2} \text{ m} = 3\times 10^4 \text{ m} = 30,000 \text{ m}. \ _\square$