1. Combined Operations with Common Fractions
Unit 10
Combined Operations with Common Fractions

2. Basic Principles of Combined Operations with Common Fractions
Follow the rules for addition, subtraction, multiplication, and division of common fractions to solve problems that combine operations with common fractions.
The first step in solving these problems is determining which operations are needed and in what order.

3. Basic Principles of Combined Operations with Common Fractions
Convert everything to the same units.
Convert all fractions used in addition or subtraction to the lowest common denominators.
Do the math necessary to solve the problem.

4. Combined Operations with Common Fractions
Example: Solve
Solve the first half of the problem:

5. Combined Operations with Common Fractions
Solve within parentheses, then add:
Remember to reduce the answer to the lowest terms.

6. Practical Problem
A patient is taking 2 1/2 milligrams (mg) of Valium tid (three times a day).
If each Valium tablet contains 5 mg, how many tablets does the patient take every day?

7. Practical Problem
Set up the problem and solve within parentheses first:
The patient takes 1 1/2 tablets each day.