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Ch. 7-Percents Review. Test Wednesday! Study! Study! Study!. Vocabulary. Percent: Is a ratio in which the first term is compared to 100. Discount: The amount to be taken off the original price. Principal: An amount of money borrowed or loaned.
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Ch. 7-Percents Review Test Wednesday! Study! Study! Study!
Vocabulary Percent: Is a ratio in which the first term is compared to 100. Discount: The amount to be taken off the original price. Principal: An amount of money borrowed or loaned. Interest: A charge for the use of money, paid by the borrower to the lender. Simple Interest:Interest paid only on the principal
Equating Percents with Fractions and Decimals Describe the shaded region as a fraction, decimal and percent. 38= X • 100 X=38% 38 = .38 100
Describe the shaded region as a fraction, decimal and percent. Fraction:______ Decimal:______ Percent: ______
Finding the Percent of a Number using Mental Math *Change the percent to a fraction that can easily be divided into the whole number. Ex. 80% of 40 is ____. 4 × 40 = 32 5
Find the Percent of a number using Mental math 1.) 20% of 50 2.) 25% of 60
Estimating the Percent of a Number *Change the percent into a fraction. Then change the whole number into one that can be easily divided by the fraction. Ex. 71% of 62 70% of 60 70 × 60 = 42 100
Estimating the Percent of a Number 1.) 42% of 367 2.) 34% of 55
Finding the Exact Percent of a Number *Remember that the “Of” number goes on the bottom. Is of Ex. 19% of 184 19 = X • 184 X=34.96 19% of 184 is 34.96.
Ex 2- 32% of _____ is 57.6. 32 = 57.6 100 X 32X=5,760 X=180 32% of 180 is 57.6.
Find the Exact Percent of a Number 1.) 25% of 16 2.) 55% of 750 3.) 64% of _____is 208. 4.) 28% of _____is 43.4
Sales Tax and Discounts *Find the percent of a number. Tax-add it back to the original number. Discount-subtract it from the original number.
Example: Discounts Kyung wants to buy a skirt from Hollister for $47.50. it is discounted 20%. What is the end price of the skirt? 20% of $47.50 $47.50-9.50=$38.00 20 = X • 47.50 100X=950 X=$9.50 (discount)
Example: Sales Tax Michael wants to buy a shirt from Zumez for $36.99. The sales tax is 5%. What is the end price? 5% of $36.99 $36.99+1.85=$38.84 5 = X • 36.99 100X=184.95 X=$1.85 (Sales tax)
1.) Noa wants to buy a pair of earrings for $14.95. The earrings are discounted 10%. What is the end price?
2.) Ross wants to buy the new Mortal Combat video game at Gamestop for $59.99. The sales tax is 6.5%. What is the end price?
Percent Increase or Decrease X = Difference between two amounts • Original Number Ex. Izzi wants to buy a pair of shoes that originally cost $48. The shoes are on sale and now cost $35. What is the percent decrease? $48-35=13 X = 13 • 48 48X=1300 X=27.1%
1.) There are 14 people in class on Tuesday. There are 20 people in class on Wednesday. What is the percent increase?
2.) Ms. Nelson also works at Express and receives a store discount. She bought a $75 skirt for $60. What is the percent decrease?
Simple Interest Interest = Principal × Rate × Time I = P × r × t Total =Principal +Interest T=P+I
Simple Interest Ex. Megan borrowed $12, 000 for 1 year at a simple interest rate of 6.75% per year. Find the amount of interest and the total amount. I=P×r×t T=P+I I=12,000×.0675×1 T=$12,000+810 T=$12,810 I=12,000×6.75×1 100 I=$810
1.) Carrington invests $15,000 for 8 years at a simple interest rate of 6.75% per year. Find the amount of interest and the total amount.
2.) Jacob invests $850 at a simple interest rate of 5.5% per year for 5 years. Find the amount of interest and the total amount.