# Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease.

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Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. Warm Up Write each fraction as a percent. 1.2.3. Write each percent as a fraction. 4. 20%5. 25%6. 60% 75% 10% 40% 3 4 1 10 2 5 1 5 1 4 3 5

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. Correct Homework

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. Problem of the Day A pair of \$100 sneakers was on sale for 50% off. Then the store manager marked them down another 30%. She then discounted the price by 20%. What is the total discount as a percent of the original price? 72%

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. A percent can be used to describe an amount of change. The percent of change is the percentage a number increases or decreases. If the amount goes up, it is a percent of increase. If the amount goes down, it is a percent of decrease. You can find the percent of change by using the following formula. % change 100 amount of change original amount =

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. % change 100 amount of change original amount = The temperature increases from 60 degrees Fahrenheit to 75 degrees Fahrenheit. What is the percent change? % change 100 (75-60) 60 = % 100 15 60 = 25% increase

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. % change 100 amount of change original amount = The price of last year’s season pass was \$750. This year it only cost \$600. By what percent did the price change? % change 100 (750-600) 750 = % 100 150 750 = 20% decrease

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. % change 100 amount of change original amount = The price of an object went from \$20 to \$23. What is the percent change? % change 100 (23-20) 20 = % 100 3 20 = 15% increase

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. % change 100 amount of change original amount = An author sold 1000 copies of his book last year. This year he sold 950 copies. What is the percent change? % change 100 (1000-950) 1000 = % 100 50 1000 = 5% decrease

Pre-Algebra 8-4 Percent Increase and Decrease 04/14/2010 Proportion and Percent #23 Today’s Plan: -Warm-Up & Correct Homework -Percent Increase and Decrease -Assignment LT: I will apply my understanding of ratios to solve problems involving proportional relationships, including percent. % change 100 amount of change original amount = Assignment: pg 418 #1-16 & 34 Tomorrow: Review assignment with substitute. Ch 7 test retakes today or tomorrow after school, or tomorrow at lunch.

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