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UNIT 5: PERCENT, RATIO, AND RATE
MATH 8
RELATING FRACTIONS, DECIMALS, AND PERCENT
Unit 5.1
Percent to Fraction
Percent to fraction
1) 19%
2) 36%
4) 92.5%
5) 47.25%
3) 85%
Step 4: Reduce to lowest termStep 3: Eliminate the decimals in the fraction
Step 2: Take out the percentage signStep 1: Divide the number by 100
Percent to Fraction to Decimal
Percent to fraction
1) 19%
2) 36%
4) 92.5%
5) 47.25%
3) 85%
to decimal• Step 1: Get the denominator in a power of 10.
• Step 2: Divide the numbers.
= 0.36
= 0.85
= 0.925
= 0.4725
= 0.19
Fraction to Decimal
If fraction has a denominator that is difficult to get to base 10, use calculator to divide
1) = 0.75
2) = 0.625
Fraction to Decimal to Percentage
Put it back to fraction with base 10- denominator Get denominator to be 100.Take the numerator as the percentage.
1) = 0.75
2) = 0.625 = 62.5%
= 75%
More Questions
Try to get the following fractions to decimal and then to percentage form
3)
4)
=0.6
=0.4725 =
= 60%
= 47.25%
CALCULATING PERCENT
Unit 5.2
Steps…
Calculating Percent of a number
Step 1: Get percent in decimal form.Step 2: Multiply decimal to the number
(i.e. 200).
Calculating Percent of a Number
0% 100% 180%
200 ??
Question 1What is 180% of 200?
Calculating Percent of a Number
Question 1What is 180% of 200?
180% = 1.8
1.8 * 200 = 360
0% 100% 180%
200 ??
Question 2
Question 2What is 37.55% of 95?
0% 37.55% 100%
?? 95
37.55% = 0.3755
0.3755 * 95 = 35.6725
Problem
Question 3Of the people who watched the Lego Movie, 30% of the viewers were adults. If there were 300 people watching over the weekend. How many of them were adults?
30% = 0.3
0.3 * 300 = 90
Terms
Cost price is the price that the store has to pay to get the merchandise
Selling price is the price that the store sells the merchandise
Question 4
Question 4
The cost price of a Wal-Mart T-shirt is $5.00. The selling price is 300% of the cost price. What is the selling price of the T-shirt? Illustrate the answer in a number line.300% = 3
5* 3 = $15.00
SOLVING PERCENT PROBLEMS
Unit 5.3
Question 1 a)
Spiderman’s height was 165cm last year. After drinking some special juice, his height increased by 25%. What is his height now?
Solution A25% = 0.25165×0.25 =41.25 cm165+ 41.25 = 206.25 cm
Solution B100% + 25% = 125% (+) if increase, (-) if decrease125% = 1.25165 × 1.25 = 206.25 cm
Question 1 b)
The effect of this juice is weight loss. In the past, Spiderman kept a constant weight of 140 lbs. But after taking the juice, his weight decreased by 30%. What is his new weight.
Solution A30% = 0.30140×0.3 =42 lbs140 - 42 = 98 lbs
Solution B100% - 30% = 70% 70% = 0.7140 × 0.7= 98 lbs
Question 2 a)
70% of a number is 63. What is the number?
Step 1: Get the percent in decimal form.Step 2: Divide the number by the decimal
0% 70% 100%
63 ??
Solution: 70%= 0.763 ÷ 0.7= 90
Question 2 b)
200% of a number is 96
0% 100% 200%
96??
Solution: 200% = 296÷ 2= 38
Percent Increase/Decrease
The price of a T-shirt in Wal-Mart increased from $20 to $25.
To find the percent increase/decreaseStep 1: Divide final value to initial valueStep 2: Subtract 100% to/from it
Solution: 25 ÷ 20
= 1.251.25 = 125%
125% - 100% = 25%
More Percent Increase/Decrease
A purse went on sale in Michael Kors. The bag’s original price was $500. After a marked down deduction, the price became $420. What was the percent decrease of the bag?
Solution: 420÷500 = 0.84 0.84= 84%
100% - 84% = 16%
SALES TAX AND DISCOUNT
Unit 5.4
GST, PST, and HST
GST – Goods and Services TaxFederal tax5%
PST – Provincial Sales TaxProvincial taxDepends on the province
HST- Harmonized Sales TaxPST + GST combinedDepends on the Province
Tax in our provinces
The following link sends you to a website showing the current taxes in each provinces
http://www.retailcouncil.org/quickfacts/taxrates
Tax questions
A pair of jeans in American Eagle cost $55. How much is the final price of this jeans in…
a) BC –(GST= 5% and PST = 7%)b) Quebec (GST=5% and PST= 9.975%)
Solution a) tax = 5% + 7% = 12% 12%= 0.12 55 × 0.12 = 6.60 55 + 6.6 = $61.60
Tax questions
A pair of jeans in American Eagle cost $55. How much is the final price of this jeans in…
a) BC –(GST= 5% and PST = 7%)b) Quebec (GST=5% and PST= 9.975%)
Solution b) tax = 5% + 9.975% = 14.975% 14.975%= 0.14975 55 × 0.14975 = 8.24 55 + 8.24 = $63.24
Discount and Taxes
A dress shirt in Banana Republic is priced at $80. For the weekend, there is an additional 20% off. How much do I have to pay considering there is a tax of 12% in BC.
Solution 1:0.2 × 80 = $1680-16 = $6464 × 0.12 = $7.6064 + 7.60 = $71.60
Double Discounts
James work at Sport Chek as a cashier. He gets an employee discount of 10% on everything he buys. He wants to buy a new pair of Nike running shoes that is regularly priced at $79.99. The shoe is currently on sale for 30% off. How much is the shoe after the discounts.Discount #110% = 0.179.99 × 0.1 = 7.99979.99 – 7.999 = 71.991
Discount #230% = 0.371.991 × 0.3 = 21.597371.991 – 21.5973 = $50.3937
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