Steps to Find Percent Change
Steps to Find Percent Change is an algebra skill from Openstax Intermediate Algebra 2E, Chapter 2: Solving Linear Equations. Percent change is calculated in two steps: first subtract the original amount from the new amount to find the amount of change, then divide the change by the original amount and multiply by 100 percent. A positive result indicates a percent increase while a negative result indicates a percent decrease.
Key Concepts
Property To find the percent change: Step 1. Find the amount of change. $$ \text{change} = \text{new amount} \text{original amount} $$ Step 2. Find what percent the amount of change is of the original amount. The amount of change is what percent of the original amount? $$\text{Percent Change} = \frac{\text{Amount of Change}}{\text{Original Amount}} \times 100\%$$.
Examples A shirt's price increased from 20 dollars to 25 dollars. Find the percent change. The change is $25 20 = 5$ dollars. The percent change is $\frac{5}{20} = 0.25$, which is a 25% increase.
A car's value decreased from 15,000 dollars to 12,000 dollars. Find the percent change. The change is $12,000 15,000 = 3,000$ dollars. The percent change is $\frac{ 3000}{15000} = 0.20$, a 20% decrease.
Common Questions
What is the formula for percent change?
Percent change equals (new amount minus original amount) divided by the original amount, then multiplied by 100 percent.
How do you know if a percent change is an increase or decrease?
If the new amount is greater than the original, the result is positive and represents a percent increase; if the new amount is less, the result is negative and represents a percent decrease.
What is the first step in finding percent change?
The first step is to find the amount of change by subtracting the original amount from the new amount.
What textbook covers steps to find percent change?
Openstax Intermediate Algebra 2E, Chapter 2: Solving Linear Equations covers percent change calculations as part of linear equation applications.