1. Conversions: Metric and Household Systems
Chapter 4
Conversions: Metric and Household Systems
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2. Conversion Slide
Use this diagram when converting dosages within the metric system
Move decimal point three places to the left for each step kg g mg
mcg
Move decimal point three places to the right for each step
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3. Unit Conversions
Determining the need for and calculating unit conversions is the first step in dosage calculations
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4. Math Tip A clue to remember the approximate equivalent
2 pounds for every kilogram
The number of kilograms weighed is about half the number of pounds weighed
1 kg lbs
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5. Approximate Equivalents
1 t = 5 mL
1 T = 3 t = 15 mL = ½ fl oz
1 fl oz = 30 mL = 6t
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6. Approximate Equivalents
1 L = 1 qt = 32 fl oz = 2 pt = 4 cups
1 pt = 500 mL = 16 fl oz = 2 cups
1 cup = 250 mL = 8 fl oz
1 kg = 2.2 lb
1 in = 2.5 cm
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7. Weight and Volume Equivalents
fl oz 6 30 t 5 mL
© Cengage Learning 2013
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8. Weight and Volume Equivalents
Weight Equivalents g 15
1,000 gr mg 60
© Cengage Learning 2013
© 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

9. Conversion Factor Method
To convert from one unit of measurement to another
Recall the equivalents
Multiply or divide
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10. Conversion Factor Method
Identify the conversion factor
Multiply by the conversion factor to convert to a smaller unit: Think larger to smaller (×)
Divide by the conversion factor to convert to a larger unit: Think smaller to larger (÷)
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11. Math Tip Shortcut for dividing 5,000 by 1,000
Move the decimal three places to the left
Eliminate unnecessary zeros
5,000  1,000 = = 5
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12. Metric Conversions with Conversion Factor Method
Multiply to convert from a larger unit to a smaller unit, or move the decimal point to the right
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13. Metric Conversions with Conversion Factor Method (Continued)
Example: 3 L = ? mL
Think: Larger to Smaller (×)
Equivalent: 1 L = 1,000 mL
3 L = 3 × 1,000 or = 3,000 mL
k h d Base d c m
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14. Metric Conversions with Conversion Factor Method (Continued)
Divide to convert from a smaller unit to a larger unit, or move the decimal point to the left
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15. Metric Conversions with Conversion Factor Method (Continued)
Example: 400 mg = ? g
THINK: Smaller to Larger (÷)
Equivalent: 1 g = 1,000 mg
400 mg = 400 ÷ 1,000 or 400. = 0.4 g
k h d Base d c m
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16. Shortcut Conversion Rule Example
Order: 125 mcg of Digoxin to be given daily
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17. Shortcut Conversion (Continued)
Supply: Digoxin 0.25 mg scored tablets
How many tablets should be administered?
0.25 mg x 1,000 mcg/mg = = 250 mcg
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18. Conversion
Set up your conversion problem so you can cancel what is given and end up with what you are converting to
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19. Conversion (Continued)
Find: 12 fl oz = ______ cup(s)
Use the formula 1 cup = 8 fl oz
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20. Conversion (Continued)
1 in = 2.5 cm
1 ft = 12 in
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21. Conversion (Continued)
1 kg ≈ 2.2 lb
150 pounds ≈ ____ kg
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22. Quick Review
Move decimal point to right to convert from a larger unit to a smaller unit
Move decimal point to left to convert from a smaller unit to larger unit
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