1. Objectives Chapter 4 Define ratio and proportion
Locate and decipher ratios in common health applications such as drug labels
Determine if two ratios are a proportion
Simplify ratios and complex ratios
Apply ratio definitions to express unit rates
Solve for x or an unknown in a proportion
Apply proportions to nutrition labels

2. Ratio & Proportion Pages 94 - 110
Ratio and proportion make up perhaps the most critical subject matter in the text, for they lay the foundation for accomplishing the more complicated math applications in the health care fields. Thus, learners need to have a solid command of ratio and proportion skills. Ratios and proportions are used to convert measurements, establish solutions, and even calculate dosages in dimensional analysis. Ratios and proportions are also very useful for quick setups and for checking one’s common sense about an answer via mental math.
Drug labels are another place that ratios are present in health care. Careful reading of the drug label will help locate the dosage of medication per tablet or per amount of solution. Notice that each label uses a specific language indicating a ratio. These formats are milligrams/milliliters (mg/mL), micrograms/milligrams (mcg/mg), mg per tablet, milligrams in milliliters (mg in mL), etc. Careful reading will help identify what is in each tablet, each milliliter of medication, etc.
Pages

3. Page 103
Overview
Ratio is a way to show a relationship between two items. Ratios simply help us compare two items, objects, or amounts.
We are always counting and comparing items in our daily lives; hours at work versus hours away from work, number of yogurts we have eaten versus the number of yogurts still in the refrigerator, and so on.
Proportion compares two equal ratios in a mathematical equation.

4. Page 105
Ratio
A ratio is used to show a relationship between two numbers. These numbers are separated by a colon (:) as in 3:4. Ratios may be presented in three formats that provide the setup for solving proportions.
3:4
3 is to 4
Ratios are always reduced to their lowest form.
Examples – page – practice 1-2: evens
Group Work – page – practice 1-2: odds

5. Ratios in Health Care Page 107
Drug labels are another place that ratios may be seen in health care. Careful reading of the drug label will help locate the dosage of medication per tablet or per amount of solution. Notice that each label uses a specific language indicating a ratio.
Another example of ratio in health care comes from dealing with insurance coverage. There is something called a medical loss ratio, which is used in managed care to measure medical costs as a percentage of premium revenues or income.
Examples – page – practice 3-4: evens
Group Work – page – practice 3-4: odds

6. Page 109
Proportion
Proportions can be applied to almost every health care profession in one way or another.
Proportions are two or more equivalent ratios or fractions in which the terms of the first ratio/fraction have the same part-to-whole relationship as the second ratio/fraction.
To test two ratios to see if they are equivalent cross multiply.
In addition to on-the-job applications, proportions provide a simple and quick method for solving many everyday math problems such as measurement conversions, recipe conversions for increasing or decreasing the amounts of ingredients, and map mileage.
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Examples – page – practice 5: evens
Group Work – page – practice 5: odds

7. Page 110
Solving for x
The ratio and proportion method of solving for x is done in two steps.
Set the ratios up like fractions. If units of measure such as inches & feet are given, place inches across from inches & feet across from feet. Then cross multiply.
Divide the answer from step 1 by the remaining number. The quotient is the answer to x.
Examples – page – practice 6-8: evens
Group Work – page – practice 6-8: odds

8. Word Problems Using Proportions
Pages 115 – 116
Word Problems Using Proportions
When solving word problems involving proportions, following these two basic steps:
Set the problem up so that the same type of elements are directly across from each another.
Multiply the diagonal numbers.
Divide the answer from step 2 by the remaining number in the problem.
Examples – page 116 – practice 9: evens
Group Work – page 116 – practice 9: odds

9. Solving for x in More Complex Problems Using Proportion
Pages 117 – 118
Solving for x in More Complex Problems Using Proportion
Decimals and fractions may appear in your proportion problems. Although the numbers may be visually distracting, the very same principles apply when solving these proportions.
Set the problem up so that the same type of elements are directly across from each another. Cross multiply.
Divide to find the missing value.
Examples – page 118 – practice 10: evens
Group Work – page 118 – practice 10: odds

10. Nutritional Application of Proportions
Pages 119 – 120
Nutritional Application of Proportions
Carbohydrates, fats, & protein provide fuel factors for our bodies. These factors are easily applied by using proportions to solve for the unknown.
Carbohydrates → 4 calories per 1 gram
Fats → 9 calories per 1 gram
Proteins → 4 calories per 1 gram
Examples – page – practice 11-12: evens
Group Work – page – practice 11-12: odds

11. Practice with Food Labels
Page 120
Practice with Food Labels
Knowing how to read food labels important because patients often need to limit their salt, sugar, and fat intake to help ensure good health.
Proportion is useful in figuring out the amounts of these ingredients when portioning – increasing or decreasing portions.
Examples – page – practice 13: evens
Group Work – page – practice 13: odds