Once
upon a time there were 20 brothers and sisters. Their mother
was a physicist, their father was a chemist, and their family
name was Measure so naturally they were named after the
International System of Units (commonly called the metric
system). SI uses 20 prefixes for describing how big or small
something is no matter what you are measuring. For example,
1000 meters is called a kilometer and 1000 grams is called
a kilogram.
Search
through this web site to help big sister Zetta find eight
of her smaller brothers and sisters. Then fill in their
names in the chart below. (The first one is filled in for
you.) How many can you find? These kids are a pretty brainy
bunch. Check out what they have to say. See the puzzle
solution for answers.
Multiples
and Submultiples 
Prefix 
Symbol 
1
000 000 000 000 000 000 000 000 = 
yotta 
Y 
1
000 000 000 000 000 000 000 = 
zetta 
Z 
1
000 000 000 000 000 000 = 
exa 
E 
1
000 000 000 000 000 = 
________ 
P 
1
000 000 000 000 = 
________ 
T

1
000 000 000 = 
giga 
G 
1
000 000 = 
________ 
M 
1
000 = 
kilo 
k 
100
= 
________ 
h 
10
= 
deka 
da 
1



0.1
= 
________

d

0.01
= 
centi 
c 
0.001
= 
milli 
m 
0.000
001 = 
micro 
µ 
0.000
000 001 = 
________ 
n 
0.000
000 000 001 = 
________ 
p 
0.000
000 000 000 001 = 
femto 
f 
0.000
000 000 000 000 001 = 
atto 
a 
0.000
000 000 000 000 000 001 = 
zepto 
z 
0.000
000 000 000 000 000 000 001 = 
________ 
y 
Created:
May 8, 2001
Last updated: August 15, 2001
Contact: inquiries@nist.gov
