7 th Grade Math Ms. Richardson

 Before, we answered all types of percent questions using proportions.  However, when you are finding the percent of a number, there is a simpler method. 1 st Step Change the percent to a decimal 2 nd Step Multiply the decimal and the number

 Find 20% of 40.  1 st Change 20% into a decimal  2 nd Multiply 0.20 x 40= 8  20% of 40 is 8

 Find the percent of a number  a.) 80% of 55 b) 30% of 90

 You can only use this method for finding the percent of a number.  If the question asks “8 is 20% of what number?”, you can not use this method.  This method is only to find the “is”.

 A decrease in the price of an item is a discount.  To find the sales price of an item:  1 st Find the amount of the discount  2 nd Subtract the discount from the original price  Example  You buy a pair of jeans that is 33% off the original price of $29. What is the sale price?  1 st Find the amount of the discount  33% of $29 = 0.33 x 29 = $ 9.57  2 nd Subtract the discount from the original price  29 – 9.57 = 19.43

 A store is selling flip-flops at 20% off their original price. What is the sale price of a pair of flip-flops originally priced at $20?  Well 20% of $20 =.20 x 20 = 4 bucks  So I subtract the discount from the original price

 Sales tax and tips are the amounts that are added to the price of purchase.  Sales tax and tips are calculated using a percent of the purchase price.  Sales tax in Louisiana is 9%  Suggested tip is 15% of your purchase at a restaurant.

At a restaurant, you order a meal that costs $12. You leave a 15% tip. The sales tax is 9%. What is the total cost of the meal? 1 st Find the tip 15% of $12 = 0.15 x 12 =$ nd Find the tax 9% of $12 = 0.09 x 12 = $ rd Add the food = $14.88 bill, tip, and tax Answer: The total cost of the meal is $14.88

 Your bill at a restaurant is $ You leave a 20% tip and are charged a 5% sales tax. What is the total cost of the meal?