Introduction - Mathematics and Statistics for the Environment - page 2

TABLE 1.1
SI Prefixes

Factor Name Symbol Factor Name Symbol

10 24 Yotta Y 10 -1 Deci d

10 21 Zetta Z 10 -2 Centi c

10 18 Exa E 10 -3 Milli m

10 15 Peta P 10 -6 Micro µ

10 12 Tera T 10 -9 Nano n

10 9 Giga G 10 -12 Pico p

10 6 Mega M 10 -15 Femto f

10 3 Kilo k 10 -18 Atto a

10 2 Hecto h 10 -21 Zepto z

10 1 Deka da 10 -24 Yocto y

■ EXAMPLE 1.2

Consider the height of the Washington Monument. We may write it as 169,000 mm, 16,900 cm,
169 m, or 0.169 km, using the units of millimeter (prefix “milli,” symbol “m”), centimeter (prefix
“centi,” symbol “c”), or kilometer (prefix “kilo,” symbol “k”).

1.3 CONVERSION FACTORS
Conversion factors are given alphabetically in Table 1.2 and are listed by unit category in Table 1.3.

■ EXAMPLE 1.3
Problem : Find degrees in Celsius of water at 72°F.

Solution:

°C = (F - 32) × 5/9 = (72 - 32) × 5/9 = 22.2

DID YOU KNOW?

The Fibonacci sequence is the following sequence of numbers:

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …

Or, alternatively,

0.1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …

Note that each term from the third one onward is the sum of the previous two . Another point to
notice is that, if you divide each number in the sequence by the next number, beginning with
the first, an interesting thing appears to be happening:

1/1 = 1, 1/2 = 0.5, 2/3 = 0.66666, 3/5 = 0.6,

5/8 = 0.625, 8/13 = 0.61538, 13/21 = 0.61904, …

Note that the first of these ratios appear to be converging to a number just a bit larger than 0.6.