1. Conversions and calculations used by Pharmacy Technicians
Pharmacy Tech Practicum

2. Vocabulary Alligation Apothecary System Diluent Dilution
Household System
International Time
Metric System
Solvent
Volume
Drip Rates
Suspension
Piggyback
Compounding
Solution

3. Math for Pharmacists/Technicians?
Wide variety of math skills needed to work in Health Care
Pharmacy Technicians may use math for a variety of reasons
Working the cash register
Compounding (mixing) drugs
Calculating Drip Rates
Calculating Dosage amounts

4. Roman Numerals Numeric System of Ancient Rome
May be used by physicians when ordering medications
Not commonly used for larger numbers in Pharmacy

5. Roman Numerals
There are four basic principles for reading and writing Roman numerals:
1. A letter repeats its value that many times (XXX = 30, CC = 200, etc.). A letter can only be repeated three times.
2. If one or more letters are placed after another letter of greater value, add that amount. VI = 6 (5 + 1 = 6)LXX = 70 ( = 70)MCC = 1200 ( = 1200)

6. Roman Numerals
3. If a letter is placed before another letter of greater value, subtract that amount. IV = 4 (5 – 1 = 4)XC = 90 (100 – 10 = 90)CM = 900 (1000 – 100 = 900)
4. A bar placed on top of a letter or string of letters increases the numeral's value by 1,000 times.XV = 15, = 15,000
Complete Exercise 4-1 pg

7. International/Military Time
Military time used exclusively in Hospitals
Orders are written 24 hours per day
Health care workers must understand exactly when order was written and when treatment should take place
Military time decreases confusion

8. Military Time Conversion Chart
Exercise 4-2 pg 111

9. Practice Quiz #1
Pg 112

10. Fractions to decimals and %
Proper- 5/12
Improper- 7/3
Mixed Number 3 ½
Fraction to decimal- Divide Numerator (top number) by the denominator (bottom number)
5/12= 5 divided by 12
Mixed Numbers must be changed to a fraction first
Denominator x Whole Number + Numerator
3 ½ = 2 x 3 + 1= 7/2 then 7 divided by 2

11. Fractions to decimals to %
Decimals to Percent
.73 x 100 = 73% or
Move the decimal over two spaces top the right
Percent to decimal
73% / 100 or =.73 or
Move the decimal two spaces to the left

12. Ratios to % 1 : 2 = ½ Divide the numerator by the denominator x 100

13. Ratios
Ratio- A relationship between two parts of a whole or between one part and a whole.
Can be written as ½ or 1:2
Used for compounding in the pharmacy
Example 1- one gram of drug in a 1000 ml solution would read as 1:1000
Example grams of a drug in 100ml of solution would read as 25:100 which can be reduced to ¼

14. Proportions A proportion is a relationship between two ratios
May be written as 1/2 = 2/4 or 1:2 :: 2:4
Proportion problems may be solved by either cross multiplying and dividing or by “means and extremes”

15. Proportions
Example # 1
The pharmacy receives an order for erythromycin suspension 125 mg to be taken TID for 10 D
How many ml do you need to fill this order?
You have 200mg/5ml
You need 125 mg to be taken TID for 10 days
Set up equation
Have=Need
200mg/5ml=125mg/x
5 x125 = 625/200=3.125ml per dose
3 x ml per day
10 (days) x = ml

16. Proportions
Example #2
You receive an order for Decadron 3mg BID for 30D
How many TAB do you need to fill this order?
Have=Need
1.5mg TAB =3 mg/x TAB
1 TAB x 3mg = 3/1.5 = 2 TAB
2 Tab/dose x 2 doses per day = 4 tablets per day
4x30=120 Tab total

17. Proportions
Quick Check 4-6 page 117

18. Proportions
Example #3
Prepare 240 mg of gentramicin IVPB (intraveneous Piggyback) using the pharmacy stock concentration of 40 mg/ml bid
Need to determine how many ml of the stock solution are needed to fill the 240 mg order
240mg/1 ml = 40 mg/x ml
Divide both sides by 40
6ml=x
Answer you will need 12 ml of solution to equal 240 mg of drug for dose given twice daily

19. Word Problems
Read through pg 119
Example 4-8

20. Proportions
Exercise 4-7 quick check pg 120
Practice quiz pg 121

21. Metric System International System of Units
Used to measure weight, distance and volume.
Table 4-3 metric prefixes
Exercise 4-8 quick check pg 122

22. Household Measurements
System of measure used in the US
Cups, tablespoons and teaspoons are common measurements
Examples 4-10, 4-11, 4-12 on page 123
Exercise 4-9 quick check pg 123

23. Apothecary System Traditional system of pharmacy, originated in Europe
Not common in pharmacies today
Dry weight measurements- grain (gr), scruple, dram, ounce and pound.
Volume- fluid ounce, dram and minim.
Example 4-13 and 4-14
Exercise 4-10 Quick Check
Exercise 4-11 Quick Check

24. Avoirdupois System Originated in Europe Common system of commerce
Items purchased and sold by the ounce and pound
Dry weights- pounds, ounces and grains
Liquid volume- Fluid ounces (fl oz), pints (pt) and gallons (gal)
Exercise 4-12 quick check

25. Quiz
Practice quiz #3 pg 127

26. Oral Syringes and Injections

27. Pediatric Dosing

28. Geriatric Dosing

29. Calculating Drip Rates

30. Dilution

31. Alligation