Powers of Ten Notation

The Metric System has conversion factors, to make the units larger or smaller as the sitaution demands. However, these units are much easier to work with, since they are simple powers of 10, rather than 12, 16, 5280, etc. And instead of inventing a whole new word to stand for the larger or smaller unit, we simply tack on a prefix to the basic unit. Some common prefixes are summarized in the table below.

If the prefix is then multiply the base unit by Examples
     
nano- 10-9
(one one-billionth)		 nanometer
nanosecond
micro- 10-6
(one one-millionth)		 microsecond
microcoulomb
milli- 10-3
(one one-thousandth)		 millimeter
milligram
centi- 1/100 centimeter
how many cents in a $?
deci- 1/10 deciliter
decibel
deca- 10 not widely used
kilo- 1000 kilogram
kilometer
Mega- 1,000,000 Megawatts
Megaparsecs
Giga- 1,000,000,000 Gigawatts
Gigacycles

So in the metric system, the prefix immediately tells us the conversion factor. The time units are the only exceptions to this: the metric system measures time in hours, not kiloseconds! Look at the table and answer the following questions:

  1. How many meters are in a kilometer?

  2. How many grams are in a milligram?

  3. How long is a microsecond?

  4. How many centimeters are in a kilometer?

  5. How many microseconds are in a day?

  6. A pill contains half a gram of medicine. How many milligrams is that?

  7. The Earth's radius is about 6400 kilometers. How many centimeters is that?

  8. If a television show lasts for 2 hours, how many "kiloseconds" is that?

Now check your answers on the next page.

Questions? Ask the designer, Jim Heath

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