Presentation on theme: "28. 29. 2 Just in case is not clear the equation is: Solve for l."— Presentation transcript:
28. 29. 2 Just in case is not clear the equation is: Solve for l
Quiz #3a: Convert the given amount to the given unit: 1.200 cm = ______ meters? 2.5 ft 3 in = _________ in? Solve each proportion: 32 36 45 y 3. 4. 5.
Quiz #3b: Convert the given amount to the given unit: 1.6 ½ ft = ______ in? 2.4 lb 7 oz = _________ oz? Hint: lb = pound oz = ounces Solve each proportion: 32 36 45 y 3. 4. 5.
Vocabulary : Percentage = % A percentage is a fraction in which the denominator is equal to 100. For example, Decimals to percentage : Fractions to percentage:.58.08.04.6 YOUR TURN Quick Review: Name: Date: Period: Topic: Percent and Change Expressed as a percent Essential Question: What strategies could help you solve a percent problem or a percent change?
How do you find the percent using the percent proportion? What percentage of 75 is 15? What percentage of 56 is 42? a = part of, b = base, p = percent a = p · b 125% of what number is 17. 5? 20% of what number is 80? A family sells a car to dealership for 60% less than they paid for it. They paid $9000 for the car. For what price did they sell the car? A dress shirt that normally costs $38.50 is on sale for 30% off. What is the sale price of the shirt? How do you find the “a” part using the percent equation? How do you find the “b” part using the percent equation?
1) What percentage of 16 is 10? 2) What percentage of 48 is 20? a = part of b = base p = percent YOUR TURN a = p · b 3) As you walk into a store you see the skate board you always wanted at a 35% discount from its original price of $39.99. What is the sale price of the skateboard? 4) 60% of what number is 13.5? 5) 150% of what number is 34? If you need help do not hesitate to ask for help!
How do you find simple interest? I = Prt You deposited $840 in a savings account that earns a simple interest rate of 4.5% per year. You want to keep the money in the account for 4 years. How much interest will you earn? I = interest P = principal r = annual interest rate t = time in years YOUR TURN You deposited $125 in a savings account that earns a simple interest rate of 1.75% per year. You earned a total of $8.75 in interest. For how long was your money in the account? 6) A savings account earns simple interest at a rate of 6% per year. Last year the account earned $10.86 in interest. What was the balance in the account at the beginning of last year?
is the ratio of the amount of change to the original amount. Percentage Change Vocabulary: = Example: Peter’s weight decreases from 60 kg to 48 kg. Find the percentage change of his weight. If the answer is positive, it means a percentage increase. If the answer is negative, it means a percentage decrease.
YOUR TURN 7) In one year, the toll for passenger cars to use a tunnel rose from $3 to $3.50. What was the percent increase? 8) The average monthly precipitation for Chicago, Illinois, peaks in June at 4.1 in. The average monthly precipitation in December is 2.8 in. What is the percent decrease from June to December?
9) David bought a car for $90,000 three years ago. He sells the car for $54,000 this year. What is the percentage change of his car’s price? When the percentage change is positive, it means there is a profit. When the percentage change is negative, it means there is a loss. Real Life: Profit and Loss Still Your Turn!
Real Life: Percent Error 10) A decorator estimates that a rectangular rug is 5ft by 8ft. The rug is actually 4ft by 8ft. What is the percent error in the estimated area? A) 0.25% B) 20% C) 25% D) 80% Yeah, You Know It. It’s Your Turn!
Pair Work: Presentations Group 1: Group 3: Group 7: Group 8: Group 4: Group 6: Group 2: If 5 pizzas serve 14 people, how many pizzas are needed for a pizza party with 76 people? You are planting a vegetable garden with 12 rows. If it took 26 minutes to plant the first 4 rows, how long will it take to plant all 12 rows of the garden? 270 min; hours 103ft; yd 30 meters; cm 43 km; cm 12 lb 3 oz; oz 5000 centimeters; meters 15% of what number is 74? Group 5: What is 30% of 241 A beauty salon buys bottles of styling gel for $6. 35 per bottle and marks up the price by 35%. For what price does the salon sell each bottle? Group 9: Group 10: You deposit $645 in a savings account that earns simple interest at a rate of 3.5% per year. How much interest will you have earned after 7 years? Find the percent change: A $1700 computer is on sale for $1175. Find the percent change: The value of a stamp collection increases from $150 to $170 in one year