metric
system) as their official system of weights and measures. Although use
of the metric system has been sanctioned by law in the US since 1866,
it has been slow in displacing the American adaptation of the British
Imperial System known as the US Customary System. The US is the only
industrialized nation that does not mainly use the metric system in its
commercial and standards activities, but there is increasing acceptance
in science, medicine, government, and many sectors of industry.

Mathematical Notation

Mathematical Power Name

10^18 or 1,000,000,000,000,000,000 one quintillion
10^15 or 1,000,000,000,000,000 one quadrillion
10^12 or 1,000,000,000,000 one trillion
10^9 or 1,000,000,000 one billion
10^6 or 1,000,000 one million
10^3 or 1,000 one thousand
10^2 or 100 one hundred
10^1 or 10 ten
10^0 or 1 one
10^-1 or 0.1 one-tenth
10^-2 or 0.01 one-hundredth
10^-3 or 0.001 one-thousandth
10^-6 or 0.000 001 one-millionth
10^-9 or 0.000 000 001 one-billionth
10^-12 or 0.000 000 000 001 one-trillionth
10^-15 or 0.000 000 000 000 001 one-quadrillionth
10^-18 or 0.000 000 000 000 000 001 one-quintillionth

Metric Interrelationships

Prefix Symbol Length, weight, Area Volume
or capacity

exa E 10^18 10^36 10^54
peta P 10^15 10^30 10^45
tera T 10^12 10^24 10^36
giga G 10^9 10^18 10^27
mega M 10^6 10^12 10^18
hectokilo hk 10^5 10^10^ 10^15
myria ma 10^4 10^8 10^12
kilo k 10^3 10^6 10^9
hecto h 10^2 10^4 10^6
basic unit - 1 meter, 1 gram, 1 meter^2 1 meter^3
1 liter
deci d 10^-1 10^-2 10^-3
centi c 1