2-9 Percents
Objectives
To solve percent problems using proportions
To solve percent problems using the percent equation
Dynamic Activity
Percents and Proportions
The problem in the Solve It involves percents. Percents are useful because they standardize comparisons to a common base of 100. In this lesson, you will solve percent problems in a variety of ways.
Essential Understanding You can solve problems involving percents using either proportions or the percent equation, which are closely related. If you write a percent as a fraction, you can use a proportion to solve a percent problem.
Take Note Key Concept: The Percent Proportion
You can represent “a is p percent of b” using the percent proportion shown below. In the proportion, b is the base, and a is a part of base b.
Algebra
Example What percent of 50 is 25?
Model
Table of Contents
- 2-1 and 2-2 Solving One- and Two-Step Equations
- 2-3 Solving Multi-Step Equations
- 2-4 Solving Equations With Variables on Both Sides
- 2-5 Literal Equations and Formulas
- 2-6 Ratios, Rates, and Conversions
- 2-7 and 2-8 Solving Proportions and Using Similar Figures
- 2-9 Percents
- 2-10 Change Expressed as a Percent
- 3-1 Inequalities and Their Graphs
- 3-2 Solving Inequalities Using Addition or Subtraction
- 3-3 Solving Inequalities Using Multiplication or Division
- 3-4 Solving Multi-Step Inequalities
- 3-5 Working With Sets
- 3-6 Compound Inequalities
- 3-7 Absolute Value Equations and Inequalities
- 3-8 Unions and Intersections of Sets
- Chapter 1 Foundations for Algebra
- Chapter 2 Solving Equations
- Chapter 3 Solving Inequalities
- Chapter 4 An Introduction to Functions
- Chapter 5 Linear Functions
- Chapter 6 Systems of Equations and Inequalities
- Chapter 7 Exponents and Exponential Functions
- Chapter 8 Polynomials and Factoring
- Chapter 9 Quadratic Functions and Equations
- Chapter 10 Radical Expressions and Equations
- Chapter 11 Rational Expressions and Functions
- Chapter 12 Data Analysis and Probability