# Using Percents to Solve Problems

## Presentation on theme: "Using Percents to Solve Problems"— Presentation transcript:

Using Percents to Solve Problems
Math 7/8

Discounts Find discount by multiplying percent (decimal value) by the price. Subtract the discount amount from the original price. EX) 30% discount on \$450 desk .30 (450) = 135 450 – 135 = 315 The sale price is \$315

Sales Tax Find amount of tax by multiplying the percent tax rate (decimal value) by the original price of the item. Add the tax amount to the original price to get the total. EX) \$39 dress and sales tax is 6% .06 (39) = 2.34 = The cost of the dress including tax is \$41.34

Tips Find tip by multiplying percent (decimal value) by the total.
Add the tip amount to the final total bill. Often times the tip is rounded to the nearest dollar EX) 15% tip on a bill of \$26.93 .15 (26.93) = 4.04 = 30.97 ***round up to \$31 total including tip

Simple Interest Review
The formula for interest is: I = prt I = interest p = principle (amount of savings or loan) r = rate (decimal form) t = time in years EX) Sarah borrowed money from the bank to buy a car. The car was \$7,800. She has to pay 4.5% interest for 36 months. How much will Sarah end up paying for her car?