2.  The formula for finding the percent increase or decrease is: Percent Increase: New –Original x 100% Original Percent Decrease: Original – New x 100% Original

3.  A value goes from 15 to 21  The DIFFERENCE is 6

5.  40% increase or decrease?  The value went from 15 to 21  Increase

6.  A value goes from 16 to 28 28-16 = 12 Increase or decrease? Increase

7.  A number goes from 32 to 24 32-24 = 8 Increase or decrease? Decrease

8.  A number goes from 20 to 30. What is the percent of change?

9.  Prices at a local electronic store have changed over the years. By what percent did the prices increase or decrease for the stereo system? Item19942004 Stereo System $98.95$135.95 Cell Phone $245$159

10.  John is at the mall and wants to buy a T-shirt that he saw last month for $20. The T-shirt now costs $25. Find the percent increase or decrease.  Janelle wants to buy a jacket at Justice for $72.00. The jacket is now on sale for $54.00. What is the percent decrease?

11.  Error is the difference between an exact value and an estimate or measured value. % Error = (experimental value – accepted value) x 100 accepted value  This is often used during science experiments and statistical analysis.

12.  Exact value of a branch is 3.273m. A student measures it and gets 3.45m. What is the percent error? (nearest hundredth) % Error = (experimental– accepted) x 100 accepted value % error = 3.45 – 3.273 x 100 = 5.41% 3.273

13.  Actual mass of a quarter = 5.67 g Experimental mass of a quarter = 5.70 g  Actual volume of a soda = 355 mL Experimental volume of a soda = 325 mL  Actual height of Mr. Baldwin = 1.75 m Measured height of Mr. Baldwin = 1.70 m

14.  Suppose Ms. Vazquez measured your index finger and said that it was 7 cm long.  Using a ruler, measure your index finger.  Calculate Ms. Vazquez’s percent error.