Biology 110 - Metric System Worksheet (15 points - Due September 7, 2005)
Penn State New Kensington

The metric system is the standard measurement system used in science and medicine.  The following are the units of measurement used in the metric system:

Metric Conversion
The metric system is favored in science and through much of the world because of the ease in which measurements can be converted.   In the metric system, conversions between different orders of magnitude are based on powers of ten (See Table 1.1), so to convert you just need to move the decimal point.

* base units we will work with in biology are meters, grams or liters

Metric Conversions:  A Visual Aid

Equals

Note:  millimeters are smaller than centimeters, but there are a larger number of millimeters in a given length.

When you convert from a larger size unit to a smaller size unit (say from cm to mm), the actual number you end up with is larger.
(2 cm converts to 20 mm)

When you convert from a smaller size unit to a larger size unit (from mm to cm), the actual number you end up with is smaller.
(30 mm converts to 3 cm)

You need to remember this relationship (it's logical, but you may find you need to remind yourself of this often to avoid confusion!) as you convert between units. 

There are two things you need to determine when converting:

1. The relationship between the units (which is a smaller unit, which is a larger unit)
2. The order of magnitude of the difference between the units (factor of 10, 100, 1000 etc)

The mechanics of conversion:

• when converting from a larger size unit to a smaller size unit,  move the decimal place to the right
• when converting from a smaller size unit to a larger size unit move the decimal place to the left
• for each factor of 10, the decimal moves one place

Some examples:

• a decimeter is larger than a centimeter by a factor of 10
  So, to convert from decimeters to centimeters, you would move the decimal place to the right one place
     Example:  5.4 dm = 54 cm
• a millimeter is smaller than a meter by a factor of 1000 (10³)
  So, to convert from millimeters to meters, you would move the decimal place to the left three places
     Example:  3400 mm = 3.4 m
• a microliter is smaller than a liter by a factor of one million (10⁶)
  So, to convert from microliters to liters, you would move the decimal place to the left 6 places

Assignment - 15 points - Due September 7, 2005
(Use separate sheet and show your work for partial credit)

1. A deciliter is smaller/larger (circle one) than a milliliter by a factor of              
   
   
2. A micrometer is smaller/larger (circle one) than a meter by a factor of              
   
   
3. A nanometer is smaller/larger (circle one) than a millimeter by a factor of             
   
   
4. A decigram is smaller/larger (circle one) than a microgram by a factor of             
   
   
5. Convert 6.0 deciliters into liters
6. Convert 0.8 kilograms into grams
7. Convert 42.0 microliters into liters
8. Convert 897.0 centimeters into meters
9. Convert 5,684.0 millimeters into meters
10. Convert 4 milliliters into microliters
11. Convert 87 micrometers into centimeters
12. Convert 206 nanograms into picograms
13. Convert 4.5 centiliters into microliters
14. Convert 34,567 millimeters into nanometers
15. Convert 3.09 micrograms into milligrams

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