Chapter 5: Conversions Within Measurement Systems Flashcards
What is the Conversion Factor?
A ratio equal to 1, used to change one unit to another without changing the value of the measurement.
What is Dimensional Analysis (DA)?
A method used for converting between units by multiplying fractions, canceling unnecessary units until the desired unit is reached.
What is Ratio and Proportion (R&P)?
A method for single-step conversions between units involving cross-multiplication and division to solve for the unknown.
List the steps for solving conversions using R&P.
- Identify the unknown unit.
- Find the known equivalent.
- Set up a fraction with the known equivalent on one side.
- Set up a fraction with the unknown unit on the other side.
- Cross-multiply and divide to solve.
Steps for solving conversions using Dimensional Analysis (DA).
1) Identify the unit of the answer needed.
2) Set up a fraction with the desired unit in the numerator.
3) Set up the next fraction so the units cancel.
4) Multiply and cancel until the desired unit remains.
How many teaspoons (tsp) are in 1 tablespoon (Tbsp)?
3 tsp = 1 Tbsp
How many tablespoons are in 1 ounce (oz)?
2 Tbsp = 1 oz
How many ounces are in 1 cup (c)?
8 oz = 1 c
Convert 1 pint (pt) to cups (c).
1 pt = 2 c
Convert 1 quart (qt) to pints (pt).
1 qt = 2 pt
Convert 1 gallon (gal) to quarts (qt).
1 gal = 4 qt
How many grams (g) are in 1 kilogram (kg)?
1 kg = 1,000 g
How many milligrams (mg) are in 1 gram (g)?
1 g = 1,000 mg
How many micrograms (mcg) are in 1 milligram (mg)?
1 mg = 1,000 mcg
How many milliliters (mL) are in 1 liter (L)?
1 L = 1,000 mL
When converting from a larger metric unit to a smaller one, do you multiply or divide?
Multiply (e.g., 1 kg = 1,000 g).
When converting from a smaller metric unit to a larger one, do you multiply or divide?
Divide (e.g., 500 mg = 0.5 g).
Convert 1 kilogram (kg) to milligrams (mg).
1 kg = 1,000,000 mg
Convert 1.2 liters (L) to milliliters (mL).
1.2 L = 1,200 mL
Convert 5.6 kg to mg.
5.6 kg = 5,600,000 mg
Convert 0.005 grams (g) to milligrams (mg).
0.005 g = 5 mg
Convert 0.002 kg to grams (g).
0.002 kg = 2 g
Convert 6.54 kg to mg using the DA method.
6.54 kg = 6,540,000 mg
What is the main unit of mass in the Apothecary System?
The grain (gr).
How many grains (gr) are approximately equal to 1 gram?
1 gr ≈ 60 mg
How many fluid drams (fl ʒ) are in 1 fluid ounce (fl oz)?
8 fl ʒ = 1 fl oz
Convert 4 fluid ounces (fl oz) to fluid drams (fl ʒ).
4 fl oz = 32 fl ʒ
Convert 15 grains (gr) to milligrams (mg).
15 gr = 900 mg
Convert 60 drops (gtt) to teaspoons (tsp).
60 gtt = 1 tsp
Convert 45 micrograms (mcg) to milligrams (mg).
45 mcg = 0.045 mg
Convert 0.25 grams (g) to milligrams (mg).
0.25 g = 250 mg
What is the shortcut rule for converting between metric units?
Move the decimal point by 3 places for each 1,000-fold difference.
What is the primary use of Dimensional Analysis (DA) in pharmacy?
To handle multistep conversions between units in pharmaceutical calculations.
What is the primary method to handle single-step conversions?
Ratio and Proportion (R&P), using cross-multiplication.
What is the abbreviation for teaspoon?
tsp
What is the abbreviation for tablespoon?
Tbsp
What is the abbreviation for pound?
lb or #
What is the abbreviation for ounce?
oz
What should you use instead of cc for volume to avoid confusion?
mL (milliliters)
How many ounces (oz) are in 1 pound (lb)?
16 oz = 1 lb
What is the conversion for 1 Tbsp to teaspoons (tsp)?
1 Tbsp = 3 tsp
What is the abbreviation for grain in the Apothecary system?
gr
How many micrograms (mcg) are in 0.25 milligrams (mg)?
250 mcg
Convert 1.75 L to mL.
1.75 L = 1,750 mL
Convert 36 kg to grams (g).
36
How many quarts (qt) are in 6 pints (pt)?
6 pt = 3 qt
Convert 0.125 mg to micrograms (mcg).
0.125 mg = 125 mcg
How many milliliters (mL) are in 0.5 liters (L)?
0.5 L = 500 mL
Convert 58,400 mL to liters (L).
58,400 mL = 58.4 L
Convert 0.05 grams (g) to milligrams (mg).
0.05 g = 50 mg
Convert 24 ounces (oz) to cups (c).
24 oz = 3 cups
Convert 1 Tbsp to mL.
1 Tbsp ≈ 15 mL
Convert 3.75 liters (L) to milliliters (mL).
3.75 L = 3,750 mL
How many gallons (gal) are in 32 ounces (oz)?
32 oz = 0.25 gal
What is the rule for moving the decimal when converting from a smaller metric unit to a larger metric unit?
Move the decimal point to the left by 3 places or divide by 1,000.
Convert 6 cups to ounces (oz).
6 cups = 48 oz
Convert 45 gtt (drops) to tsp.
45 gtt ≈ 0.75 tsp
How many fluid drams are in 4 fluid ounces?
4 fl oz = 32 fl drams
What are the most common weight units used in pharmacy in the metric system?
Kilogram (kg), gram (g), milligram (mg), microgram (mcg).
What are the most common volume units used in pharmacy in the metric system?
Liter (L) and milliliter (mL).
Convert 500 mL to liters (L).
500 mL = 0.5 L
How many pints (pt) are in 4 cups (c)?
4 cups = 2 pints
What is the apothecary system symbol for fluid ounce?
The symbol for fluid ounce is fl ℥.
How do you convert grains (gr) to milligrams (mg)?
Multiply the number of grains by approximately 60 to get milligrams (e.g., 1 gr ≈ 60 mg).
Convert 125 mg to grams (g).
125 mg = 0.125 g
Convert 0.5 mg to grams (g).
0.5 mg = 0.0005 g
What should be used to measure liquid medications at home?
Calibrated medication cups or oral syringes should be used to measure liquid medications at home.
Convert 2.5 grams (g) to milligrams (mg).
2.5 g = 2,500 mg
Convert 3.56 grams (g) to milligrams (mg).
3.56 g = 3,560 mg
How many milliliters (mL) are in 8 ounces (oz)?
8 oz = 240 mL
Convert 0.04 kg to grams (g).
0.04 kg = 40 g
Convert 2 gallons to quarts.
2 gallons = 8 quarts
Convert 2 quarts to liters (L).
2 quarts ≈ 1.89 liters (L)
What are the most common units of mass in the apothecary system?
Grain (gr) and dram (ʒ).
How do you convert between metric and household systems?
Use conversion factors such as 1 tsp = 5 mL, 1 oz = 30 mL, and 1 cup = 240 mL.
Convert 0.5 tsp to milliliters (mL).
0.5 tsp = 2.5 mL
Convert 250 mg to grams (g).
250 mg = 0.25 g
