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0.4Self-Evaluation

The introductory part of a book like this is hard to write, because every

student arrives at this starting point with a different preparation. One

student may have grown up in another country and so may be completely

comfortable with the metric system, but may have had an algebra course in

which the instructor passed too quickly over scientific notation. Another

student may have already taken calculus, but may have never learned the

metric system. The following self-evaluation is a checklist to help you figure

out what you need to study to be prepared for the rest of the course.

If you disagree with this statement...you should study this section:

I am familiar with the basic metric units of meters,

kilograms, and seconds, and the most common metric

prefixes: milli- (m), kilo- (k), and centi- (c).

0.5 Basics of the Metric System

I know about the Newton, a unit of force0.6 The Newton, the Metric Unit of Force

I am familiar with these less common metric prefixes:

mega- (M), micro- (

µ

), and nano- (n).0.7 Less Common Metric Prefixes

I am comfortable with scientific notation.0.8 Scientific Notation

I can confidently do metric conversions.0.9 Conversions

I understand the purpose and use of significant figures.0.10 Significant Figures

It wouldn’t hurt you to skim the sections you think you already know

about, and to do the self-checks in those sections.

0.5Basics of the Metric System

The metric system

Units were not standardized until fairly recently in history, so when the

physicist Isaac Newton gave the result of an experiment with a pendulum,

he had to specify not just that the string was 37

7

/

8

inches long but that it

was “37

7

/

8

London inches long.” The inch as defined in Yorkshire would

have been different. Even after the British Empire standardized its units, it

was still very inconvenient to do calculations involving money, volume,

distance, time, or weight, because of all the odd conversion factors, like 16

ounces in a pound, and 5280 feet in a mile. Through the nineteenth

century, schoolchildren squandered most of their mathematical education

in preparing to do calculations such as making change when a customer in a

shop offered a one-crown note for a book costing two pounds, thirteen

shillings and tuppence. The dollar has always been decimal, and British

money went decimal decades ago, but the United States is still saddled with

the antiquated system of feet, inches, pounds, ounces and so on.

Every country in the world besides the U.S. has adopted a system of

units known in English as the “metric system.” This system is entirely

Chapter 0Introduction and Review