Microbiology Demystified

It is usually at this point in the study of microbiology when some students
begin a slow panic because they must learn a new measurement system. Don’t
panic! The metric system is very easy to learn—much easier to learn than the
U.S. measurement system.

THE PREFIX FIXES ALL YOUR PROBLEMS

The first trick to learning the metric system is to memorize the meaning of six
prefixes. In the metric system, each prefix means that a meter is either multiplied
or divided by a multiple of 10.
The second trick to learning the metric system is to learn how to multiply and
divide by 10. This is easy because all you need to do is move the decimal point.
The decimal point is moved to the right one place when multiplying by 10. The
decimal point is moved to the left one place when dividing by 10.
Let’s see how this works. First, multiply 1 meter by 10.

1 × 10 = 10

Now convert a meter to a decimeter. From the previous section, you know
that a decimeter is one-tenth of a meter, which means that you must divide
by 10.

1 ÷ 10 =0.10

Table 3-1 shows the prefixes for the metric system and their equivalent in
meters.

CHAPTER 3 Observing Microorganisms^49

Prefix Value in Meters

Kilo (km) (kilo = 1,000) 1,000 m

Deci (dm) (deci = 1/10) 0.10 m

Centi (cm) (centi = 1/100) 0.01 m

Milli (mm) (milli = 1/1000) 0.001 m

Nano (nm) (nano = 1/1,000,000,000) 0.000000001 m

Pico (pm) (pico = 1/1,000,000,000,000) 0.000000000001 m

Table 3-1. Prefixes