1. 1. Do Warmups 2. Check HW 1.How do you find a percent, based on part of a whole? 2.What percent of 52 is 39? 3.What percent of 78 is 48.75? 4.What percent of 90 is 110? Round to the nearest hundredth of a percent.

2. 4.2: Percent of Change

3. Percents of Increase/Decrease A very common way of using percents is to talk about the percent by which an amount changes. For example: At the beginning of the year, I had 20 students in time block 1. Now, I have 18. The number of students decreased by 2. 2 is 10% of 20 (you can use percent equation to check), so there was a 10% decrease in the number of students.

4. Finding the percent of change Problem: Yesterday, I had $30 in my savings account. Today, I have $45. A.Was this an increase or a decrease? B.What was the percent of change? How to: 1. Find the amount of change. 2. Find what percent the amount of change is compared to the original amount.