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Days 7-8. Sale! and Error Lesson Plan. Percent Change. The percentage by which a number changes. It is the ratio as a percent. When is it a percent of increase/decrease?. Percent of _______ is when the original amount goes up. increase.
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Days 7-8 Sale! and Error Lesson Plan
Percent Change The percentage by which a number changes It is the ratio as a percent. When is it a percent of increase/decrease? Percent of _______ is when the original amount goes up. increase Percent of _______ is when the original amount goes ____. decrease down The price of an item went from $2 to $3. What is the percent change? Is it an increase or decrease?
Leopard Chain Hoodie Was $79, now $65 What is the percent change for each item? Black Denim Zipper Jacket Was $89, now $72
Luckily after the sale prices, there is an additional 20% off everything you purchase. If you buy the denim jacket ($72) and the bracelet, how much will your total be after 20% is taken off? And of course, you need to accessorize… Rope Style Bracelet $20.00
Converse Weapon EVO Was $80, now $65 Nike Air Max Lebron VII now $160, will be $140 What is the percent change for each item? If there was an additional 20% of the Nike Air Max Lebron VII ($140), how much would they be?
Greatest Possible Error and Percent Error The greatest possible error is ½ of the unit being used to measure inches cm and mm How long is this line segment? About 5.2 cm or 52 mm The greatest possible error is…? .05 cm or .5 mm 5.15 cm 5.25 cm So our measurement could be any where from _____ to _____
Percent error is Our line segment was 5.2 cm and our greatest possible error is .05 cm. What’s our percent error? Percent error = What is the percent error for the square with length of 5.2 cm? 27.04 – 25.5 = 1.54 27.6 – 27.04 = .56 Least length is 5.15 cm, greatest length is 5.25 cm Least area is ≈ 26.5 cm², greatest area is ≈ 27.6 cm² Percent error is Measured area is 27.04 cm² Which area is farthest from our measured area? (Our greatest possible error)
What if our measurements are not all the same? A small box has the measurements of Length = 20 cm Width = 35 cm Height = 10 cm .5 cm What is the greatest possible error? Greatest measurements Length = 20.5 cm Width = 35.5 cm Height = 10.5 cm Least measurements Length = 19.5 cm Width = 34.5 cm Height = 9.5 cm What is the…. Least (minimum) volume Measured Volume Greatest (maximum) Volume V = 7000 cm³ V = 6391 cm³ V = 7641 cm³ Greatest possible error is….? 641 cm³ 7000 cm³ – 6391cm³ = 609 cm³ 7641 cm³ – 7000 cm³ = 641 cm³