Lesson 2, unit 4 - percents



Gr. 8 MathUnit 4 – PercentStudent CopyLesson 28.N.3 – Calculating Percent Lesson Focus:To calculate percents from 0% to greater than 100%.Discussion:Have you ever used a photocopier to reduce or enlarge a picture?To choose the size of the image, you must select a percent.171051622525200Examine the photo below to answer the following questions.Which percents might you choose to reduce the picture?Which percents might you choose to enlarge the picture?Explain what each of the percents will do to your image.44187346921500Investigation:Work with a partner.Copy this shape on a sheet of 1 cm grid paper.Redraw this shape so that each segment is 150% of the length shown.On a new piece of grid paper draw your own shape. Choose a different percent between 100% and 200%. Repeat step a.Conclusion:What strategies did you use to create your enlargements?What do you notice about the lengths of corresponding line segments on the original shape and the enlarged shape?Recall that when the whole is 1.0, you know that:100% = ____________311150730250010% = _____________ 1% = _____________ We can extend this pattern to write percents less than 1% as decimals:0.1% = _____________101092088900000.5% = _____________We can use number lines to show percents between 0% and 1%.Ex. 1Use the number line below to show 0.2%.We can also use number lines to write percents greater than 100%.Ex. 2Place the following percents on the number line below.101%110%150%200%34636427662941968892731660023187322799770031848128817400Ex. 3a. Write 210% as a decimal._____________b. Shade the hundreds chart below to show 210%.Percents greater than 100% are used by store owners to calculate the _____________ of the items that they sell. A store has to make a _____________ – they do this by selling goods for more than the goods cost them to buy.A store manager buys merchandise from a ______________.The price the manager pays is called the _________ price.The manager _________ ____ the cost price to arrive at the ______________ price for the customer. The markup is the ____________.Therefore, _________ Price + __________ = _____________ PriceEx. 4The cost price of a winter coat is $80. The selling price of the coat is 230% of the cost price. What is the selling price of the coat? Illustrate the answer with a number line.118427525019000Ex. 5In 2004, the population of First Nations people living on reserves in Alberta was 58 782. About 0.28% of these people belonged to the Mikisew Cree Band.About how many people belonged to the Mikisew Cree Band?Estimate to check if the answer is reasonable.Illustrate the answer with a number line.135081821526500Assignment Do #4 – 15 p. 246 (need hundreds charts for #4)If done the above questions, challenge yourself with #16 – 19 p. 247 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download