HI-1017: Pharmacy Technician Module 14 - Metric System
Slide 1 Main Objectives The Metric System Converting Metric Units Practice Exercises
Slide 2 The Metric System The Metric System Units of Measurement Prefixes
Slide 3 The Metric System The 3 basic units of measurement in the metric system are Meter (m) = basic unit of length Liter (l or L) = basic unit of volume Gram (g) = basic unit of weight
Slide 4 Units of Measurement All additional units of measure are based on these 3 basic units: Centimeter (cm) and millimeter (mm) are units of length Centiliter (cl) and milliliter (ml) are units of volume Kilogram (kg) and milligram (mg) are units of weight
Slide 5 Prefixes Each prefix that is used in the metric system represents a multiple or subdivision of ten Prefix Abbreviation Multiples or subdivisions Kilo k 1000 Hecto h 100 Deka dk 10 Gram, Liter, Meter g, l, m 1 Deci d 0.1 or 1/10 Centi c 0.01 or 1/100 Milli m 0.0001 or 1/1000 Micro mc 0.0000001 or 1/1000000 Nano n 0.0000000001 or 1/1000000000
Slide 6 enotes Kilo Hecto Deka BaseDeci Centi Milli * * Micro 1000 100 10 1. 0.1 0.010.001 0.000001 K H D B. D C M * * M
Slide 7 Converting Metric Units Converting Units of Measurement Converting From a Small Unit to a Larger Unit Converting From mg to g Converting From ml to L Converting From a Large Unit to a Smaller Unit Converting From kg to g Converting From kg to mcg Multiplying Metric Values Dividing Metric Values Remember
Slide 8 Converting Units of Measurement Remember with the metric system: When going small to large = divide When going large to small = multiply
Slide 9 Converting From a Small Unit to a Larger Unit Follow this example When converting from a small unit to a larger unit, make sure your number increases proportionately Step 1: Find the unit on the chart to determine its subdivision Step 2: Divide by the subdivision
Slide 10 Converting From mg to g Convert 5675 mg to g Step 1: Find milli and count how many times you have to move to gram Three times to the left indicating that a gram is 1,000 times larger than a milligram Step 2: Divide by the subdivision 5,675/1,000 = 5.675 grams
Slide 11 Converting From ml to L Convert 5786 ml to L Step 1: Find milli and count how many times you have to move to liter. Three times to the left indicating that a liter is 1,000 time larger than a milliliter Step 2: Divide by the subdivision 5,786/1,000 = 5.786 liter
Slide 12 Converting From a Large Unit to a Smaller Unit Follow this example When converting from a larger unit to a small unit, make sure your number decreases proportionately Step 1: Find the unit on the chart to determine it s subdivision Step 2: Multiply by the subdivision
Slide 13 Converting From kg to mcg Convert 0.200897 kg to mcg Step 1: Find kilo and count how many times you have to move to mcg 9 times to the right indicating that a microgram is 1,000,000,000 times smaller than a kilogram Step 2: 0.200897 x 1,000,000,000 = 200,897,000 mcg
Slide 14 Converting From kg to g Convert 72 kg to g Step 1: Find kilo and count how many times you have to move to grams 3 times to the right indicating that a kilogram is 1,000 times larger than a gram Step 2: 72 x 1,000 = 72,000 grams 1,000 grams = 1 kilogram
Slide 15 Multiplying Metric Values Follow this example When multiplying metric values by multiples of ten, move the decimal point one place to the right for each zero in the multiplier Step 1: Move the decimal point one place to the right for each zero in the multiplier 10 x 84.67 = 846.7 1,000 x 0.325 = 325
Slide 16 Dividing Metric Values Follow this example Move the decimal point one place to the left for each zero in the divisor Step 1: 74.67 100 =? Move the decimal two spaces to the left = 0.7467 Step 2: 0.67 1,000 =? Move the decimal three spaces to the left = 0.00067
Slide 17 Remember Convert everything to the same units when solving metric problems 1 kg + 300 g =? 1 kg = 1 x 1,000 1,000 g + 300 g = 1,300 g 1 kg + (300/1,000 kg) 1 kg + 0.3 kg = 1.3 kg
Slide 18 Practice Exercises Practice Exercise: 1 Practice Exercise: 2 Practice Exercise: 3 What did we learn?
Slide 19 Practice Exercise: 1 The gas station is only 2.6 kilometers from my home. How many meters would I travel round-trip to the gas station and back home? Step 1: Determine what needs to be solved Step 2: Convert large to small (multiply) Step 3: Remember that the keyword, round-trip, means you must multiple by 2
Slide 20 Practice Exercise: Answer 1 Answer: Step 1: Determine what needs to be solved 2.6 km to m Step 2: Convert large to small (multiply) 2.6 x 1,000 = 2,600 m Step 3: Remember that the keyword, round-trip, means you must multiple by 2 2,600 m x 2 = 5,200 m
Slide 21 Practice Exercise: 2 How many 120 ml bottles can be filled from 3.84 L of a cough syrup? Step 1: Determine what needs to be solved Step 2: Convert to the same unit, L to ml (large to small, multiply) Step 3: Solve the division problem
Slide 22 Practice Exercise: Answer 2 Answer: Step 1: Determine what needs to be solved 3.84 L 120 ml =? Step 2: Convert to the same unit, L to ml (large to small, multiply) 3.84 x 1,000 = 3,840 ml Step 3: Solve the division problem 3,840 ml 120 ml = 32 bottles
Slide 23 Practice Exercise: 3 How many 30 mg thiamine HCI capsules can be prepared from 0.0009 kg of thiamine HCI? Step 1: Determine what needs to be solved Step 2: Convert to the same unit, kg to mg (large to small, multiply). Ask yourself, how many moves it took to get to milli (6) Step 3: Solve the division problem
Slide 24 Practice Exercise: Answer 3 Answer: Step 1: Determine what needs to be solved 0.0009 kg 30 mg =? Step 2: Convert to the same unit, kg to mg (large to small, multiply). Ask yourself, how many moves it took to get to milli (6) 0.0009 x 1,000,000 = 900 mg Step 3: Solve the division problem 900 mg 30 mg = 30 capsules
Slide 25 Practice Exercise: 4-5 Convert the following metric units: 4. 55 g =? mg Convert large to small (multiply) 5. 72 mg =? mcg Convert large to small (multiply)
Slide 26 Practice Exercise: 6-8 6. 105 L =? ml Convert large to small (multiply) 7. 355.56 ml =?L Convert small to large (divide) 8. 8,023,766 g =? kg Convert small to large (divide)
Slide 27 Practice Exercise: 9-10 9. 0.002289 ml =? L Convert small to large (divide) 10. 635 g + 0.58 kg + 428,970 mg =?g Convert everything to the same unit (gram) Convert mg to g (small to large, divide) Convert kg to g (large to small, multiply)
Slide 28 Practice Exercise: Answers 4-7 Answers 4. 55 g =? mg 55 x 1,000 = 55,000 mg 5. 72 mg =? mcg 72 x 1,000 = 72,000 mcg 6. 105 L =? ml 105 x 1, 000 = 105,000 ml 7. 355.56 ml =?L 355.56 1,000 = 0.35556 L
Slide 29 Practice Exercise: Answers 8-10 8. 8,023,766 g =? kg 8,023,766 1,000 = 8,023.77 kg 9. 0.002289 ml =? L 0.002289 1,000 = 0.0000002289 L 10. 635 g + 0.58 kg + 428,970 mg =?g 428,907 1,000 = 428.9 g 0.58 x 1, 000 = 580 g 635 g + 580 g + 428.9 g = 1,643.9 g
Slide 30 What did we learn? The Metric System Units of Measurement Converting Metric Units Practice Exercises
Review Questions: 1. Convert 25 kg to g. a. 25,000g b. 0.025 g c. 2500 g d. 250 g 2. Convert 982 mg to g. a. 982,000 g b. 0.982 g c. 9 g d. 9.82 g 3. Convert 0.0298 m to mm. a. 2 mm b. 0.0000298 mm c. 29.8 mm d..298 mm 4. Convert 0.200887 kg to mcg. a. 200 mcg b. 200,887,000 mcg c. 0.00000020087 mcg d. 20,887 mcg 5. 1 g = 1000 mg. How many milligrams are in 5.5 g? a. 5500 mg b. 550 mg c. 0.0055 mg d. 55 mg 6. The number of milligrams in 3,120 mcg is: a. 3,120,000 mg b. 0.312 mg c. 3.12 mg d. 3,120 mg
7. The total volume in milliliters of 312 ml, 3.12 L and 312L is: a. 327.12 ml b. 315,432 ml c. 31,543.2 L d. 312,543 ml 8. The number of milliliters left in a 4-liter bag of normal saline solution after you remove 50 ml, 250 ml, 2.5L and 750 ml is? a. 3,550 ml b. 450 ml c. 50 ml d. 350 ml 9. The number of milligrams of imiperiem (Primaxin) remaining in a 5 g vial after 250 mg are removed is? a. 4,750 mg b. 47 mg c. 4 g d. 745 mg 10. Sally purchased a pound of coffee. If a pound weighs 454 g, how many pots of coffee can be prepared if each pot requires 22,700 mg of ground coffee? a. 10 pots b. 20 pots c. 25 pots d. 15 pots
Answer Key: 1. A (Convert large to small) will need to multiply 25 * 1000 = 25,000 g. 2. B (Convert small to large) will need to divide 982 / 1000 = 0.982 g. 3. C (Convert large to small) will need to multiply 0.0298 * 1000 = 29.8 mm. 4. B (Convert large to small) will need to multiply 0.200887 *1,000,000 = 200,887,000 mcg. 5. A Convert g to mg - (Large to small) - will need to multiply 5.5 g * 1000 = 5500 mg. 6. C (Convert small to large) will need to divide 3120 / 1000 = 3.12 mg. 7. B Must convert all to one unit ( ml) Add all numbers 3.12 L to ml - (Large to small)- multiply 3.12 * 1000 = 3120 ml 312 L to ml - (Large to small) - multiply 312 * 1000 = 312,000 ml 312 + 3120 + 312,000 = 315,432 ml 8. B Must convert to one unit (ml) Add the numbers Convert the fluid from L to ml Subtract the answers from the amount of fluid in the bag. 2.5 L to ml - (large to small) - multiply 2.5 * 1000 = 2,500 ml 50 + 250 + 2500 + 750 = 3550 ml 4 L to ml - (large to small) - multiply 4 * 1000 = 4000 ml 4000 ml - 3550 ml = 450 ml
9. A Convert all to the same unit (mg) Subtract the answer from 250 mg 5g to mg - (large to small) - multiply 5 * 1000 = 5000 mg 5000 mg - 250 mg = 4750 mg 10. B Convert all to the same unit (g to mg) 4 g to mg (large to small) - multiply 454 * 1000 = 454,000 mg 454,000 / 22,700 = 20 pots