1. CHAPTER 6
CALCULATIONS

2. CHAPTER OUTLINE Numbers Fractions Decimal Numbers Significant Figures
Measurement
Equations & Variables
Ratio & Proportion
Percents & Solutions
Alligation
Powder Volume
Children’s Doses
Calculations for Business
Review

3. ROMAN NUMERALS

4. ROMAN NUMERALS Positional notation
When the second of two letters has a value equal to or smaller than that of the first, add their values
ixvi = = 66
When the second of two letters has a value greater than that of the first, subtract the smaller from the larger
xc = 10 subtracted from 100

5. FRACTIONS Numerators Denominators Reciprocals
Adding and subtracting fractions
Multiplying and dividing fractions

6. DECIMAL NUMBERS
Multiplying decimals
Significant figures

7. SIGNIFICANT FIGURES Four rules for assigning significant figures:
1. Digits other than zero are always significant.
2. Final zeros after a decimal point are always significant.
3. Zeros between two other significant digits are always significant.
4. Zeros used only to space the decimal are never significant.

8. MEASUREMENT Metric system Avoirdupois system Apothecary system
Household units
Measuring temperature

9. METRIC SYSTEM LIQUIDS

10. METRIC SYSTEM SOLIDS

11. AVOIRDUPOIS SYSTEM

12. APOTHECARY SYSTEM

13. HOUSEHOLD UNITS

14. TEMPERATURE

15. RATIO & PROPORTION
A ratio states a relationship between two quantities
Two equal ratios form a proportion

16. PERCENTS & SOLUTIONS Percent Weight-to-Volume Percent Volume-to-Volume
Grams per 100 milliliters
Percent Volume-to-Volume
Milliliters per 100 milliliters
Milliequivalents
mEq

17. MILLIEQUIVALENTS

18. COMMON ELECTROLYTES

19. ALLIGATION

20. POWDER VOLUME
FV = D + PV

21. CHILDREN’S DOSES Clark’s Rule Young’s Rule Body Surface Area
Body Weight

22. BUSINESS CALCULATIONS
Selling prices
Discounts
Gross profit
Net profit