CHAPTER 5 ■ NUMBERS AND UNITS
To avoid errors, the number of digits in long numbers is usually reduced in a standardized way.
Referring to Table 5-1, instead of writing 10,000,000, it can be reduced to 10 M.10,000,000 = 10 million = 10 mega = 10 M
Figure 5-1. Quick! How large of a number? 158 million? 15 million? 1.5 million?
Table 5-1. Metric Powers of a Thousand
Amount Multiplier Prefix Abbreviation
trillion 1,000,000,000,000 tera- uppercase T
billion 1,000,000,000 giga- uppercase G
million 1,000,000 mega- uppercase M
thousand 1,000 kilo- lowercase k
thousandth 0.001 milli- lowercase m
millionth 0.000001 micro- Greek m or lowercase u
billionth 0.000000001 nano- lowercase n
trillionth 0.000000000001 pico- lowercase p
Notice that the million multiplier has six zeros (see Table 5-1) and we removed six zeros from our
original number. So, the M is just taking the place of the six zeros we chopped off.
If, for some reason, it is helpful to retain some of the zeros (such as for comparison’s sake), a smaller
multiplier can be used:
10,000,000 = 10,000 thousand = 10,000 kilo = 10,000 k
Notice that the thousand multiplier has three zeros (see Table 5-1) and we removed only three zeros
from our original number. So, the k is just taking the place of the three zeros we chopped off.