1. Percent Change

2.  TODAY’S STANDARD: TODAY’S STANDARD:  CCSS.MATH.CONTENT.7.RP.A.3 Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error. CCSS.MATH.CONTENT.7.RP.A.3  Your goal is to demonstrate your mastery of this topic by solving at least 75% of percent change problems correctly on the exit ticket.

3.  To find out how much something changed, we normally subtract.  Example: I used to have 10 books but now I have 8. My number of books changed by 10 – 8 = 2

4.  However, losing 1 grain of rice from a bowl is meaningless while losing 1 out of 2 Twix bars would be devastating.  Therefore, finding the percent change can be useful.

5.  The formula for percent change is  Example: A hat used to cost $10. Now it costs $12. What was the percent change?

6.  There used to be 5 trees. Now there are 8. What is the percent change?

7.  An item is listed at $1.25 but after tax I paid a total of $1.35. What percent was the tax?