Applying percents

Understanding Cross multiplying  Proportions are equal, what do we notice about the cross products

Percent Review  Percent means parts per 100. The symbol is % Example: 25% means 25 per

Percent Proportion CCompares part of a quantity to the whole quantity, called the base, using a percent. TThe percent proportion is: part whole percent 100 = a b p =

Percent Proportion.  What number is 30% of 150? a = Cross multiply. 100a = a = 45 So 45 is 30% of Each box represents How much of 150? 15

Proportions for Percent Problems Part (is) Whole (of) 100 Percent The variable can be placed in the Part, Whole, or Percent.

Proportions for Percent Problems Part Whole 100 Percent Louis got 40 out of 50 correct on his test. What is his percent correct? x 50x = 40  x = x = 80 Louis got 80% right.

Proportions for Percent Problems Susan answered 90% of the questions from an online survey. If she has answered 18 questions, how many questions were on the survey? 18 x x = 20 The survey had 20 questions. Part Whole 100 Percent

Proportions for Percent Problems Five hundred students applied to Jordan’s IB magnet. How many will get accepted if Jordan IB only accepts 40% ? x x = students 200 students will be accepted into Jordan’s IB magnet. Part Whole 100 Percent

Discounts Caleb bought a suit that is 40% off. The original price of the suit is $360. How much did he pay for the suit? What is the discount? What is the sale price? Understanding the problem DiscountPrice you pay Price you pay is what percent? Discount is what percent?

DiscountPrice you pay

 Price you pay  Discount Steve bought a jacket that was priced at $80. Find the sales price and discount if the jacket was 20% off

Discounts (proportions) Sheila bought a dress that is 30% off. The original price of the dress is $150. What is the discount? What is the sale price?  Price you pay Discount

Commission Phillip makes 8% commission at AA Appliance store. His sales last month were $15,000. What was his commission last month? Phillip made $1200 in commission! Part Whole 100 Percent

Sales Tax Example 5% sales tax on a $55 dress  What is it?  A percent of the total price  How can you write this as a decimal?  How do you determine the amount you pay?  Full price + t ax  How can you write this as a decimal?  Now multiply by the price

Sales Tax (proportion) Steve bought a jacket that was priced at $80. Find the sales tax and price including tax if the sales tax is 6%. Step 1: Calculate the sales tax Step 2: Add the sales tax to the price The sales tax is $4.80 $80.00 pirce sales tax $84.80 price after tax

Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 7 Sales Tax (equation) Felicia is buying a pair of steel toe work boots for $80. Find the sales tax and price including tax if the sales tax is 9%. Step 1: Calculate sales tax Step 2: Add the Sales tax to the original price The sales tax is $7.20 $80.00original price sales tax $87.20 Total price 6-5 Applying % increase and decrease Whole Percent = Part

Total Price (multi- step problem) Lupe is buying a Wii console that regularly sells for $220. It is on sale for 15% off and the tax rate is 9%. How much will she pay for the Wii? Step 1: Find the price you pay

Total Price (cont.) Lupe is buying a Wii console that regularly sells for $220. It is on sale for 15% off and the tax rate is 9%. How much will she pay for the Wii? Step 2 Find the sales tax Step 3 Find the total price = Sales price = $187 The total price of the Wii is $ Sales price + tax = Total price

Profit Marilee's Travel Agency makes 20% profit on all tickets sold. Last month Marilee’s Travel Agency made $60,000 in profit, what were the total sales last month? Marilee’s total sales were $300,000. Whole Percent = Part s 20% = 60,000 s 0.20 = 60, s = 300,000

Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 7 Simple Interest Interest = Principal  rate  time I = P  r  t Interest: the amount of money paid to you on savings, or paid by you on money borrowed rate: the percent charged or paid (must be changed to a decimal or fraction) Principal: the initial amount of money time: measured in years 6-7 Applying Simple and Compound Interest

Simple Interest You have $5000 in a savings account earning 3% interest. How much interest will you earn in 2 years? Step 4 Your savings account will have earned $300 in interest in 2 years.

Percent of Increase At Julio’s Computers they buy computers for $500 and sell them for $650. What is the percent of increase? 1.Find the amount of change between the old price and new price 650 — 500 = 2.Use The percent of increase is 30%. Original Amount of Change Change to percent or Change to decimal Set up a proportion

Percent of Increase At Kat’s Computers they buy computers for $250 and sell them for $400. What is the percent of increase? 1.Find the amount of change between the old price and new price 400 – 250 = 150 p = 0.6 Change to percent p = 60% The percent of increase is 60%. Original Amount of Change

Percent of Decrease Kat’s Computers is having a sale. They are advertising a $1000 computer for $600. What is the percent of decrease? 1.Find the amount of change between old price and new price 1000―600 = 400 p = 0.4 Change to percent Change to percent p = 40% The percent of decrease is 40%.