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7.7 Percents7.8 Percents, Decimals and Fractions
1
I can convert numbers into percents
I can transform numbers from one form to another
Copyright © 2000 by Monica Yuskaitis
Compare percent, decimal and fractions
50% .50 50 100
12= = =
Decimal FractionFractionSimplifiedPercent
Copyright © 2000 by Monica Yuskaitis
50 % Means50 parts out of 100 or 50 hundredths.
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
Copyright © 2000 by Monica Yuskaitis
• 25% means ¼• 25% of 8 lemons is 2 lemons
=25% of
Copyright © 2000 by Monica Yuskaitis
Comparing Fractions & Percents
25% .25 25 100
14= = =
Decimal FractionFractionSimplifiedPercent
Copyright © 2000 by Monica Yuskaitis
25 % Means25 parts out of 100 or 25 hundredths.
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
7.9 Percent ProblemsI can solve real world problems involving percents
7
Find 35% of 20.7 or 7.00
d. Why is seven right?
20x .35
100607.00
7.10 Applying PercentsI can solve percent problems that involve discounts, tips and sales tax
9
Review from yesterday….Find the percent of each number.
1. 75% of 300
2. 93% of 56
3. 32% of 128
4. 9% of 60
225
52.08
40.965.4
Sales tax is an amount added to the price of an item.
sales tax = price • sales tax rate total cost = price + sales tax
Sales tax
A tip is an amount added to a bill for service. tip = bill • tip rate total cost = bill + tip
Tips
A discount is an amount that is subtracted from the regular price of an item. discount = price • discount rate total cost = price – discount
Discounts
Common Uses of Percents
Percent Tips…..
• You can find 10% of a number by moving the decimal point one place to the left.
• You can find 1% of a number by moving the decimal point two places to the left.
• You can find 5% of a number by finding one-half of 10% of the number.
To multiply by 0.10, move the decimal point one place left.
Remember!
A fishing store is having a 10% off sale. If Gerald wants to buy a fishing pole whose regular price is $39.95, how much will he pay for the pole after the discount?
Discounts
Ben’s dinner bill is $7.85. He wants to leave a tip that is 15% of the bill. How much should his tip be?
Tips
Ann is buying a dog bed for $29.75. The sales tax rate is 7%. How much will the total cost of the dog bed be?
Sales Tax
There is a discount of 25% off on a $60 pair of shoes. How much are the shoes?
$15
c. Why is fifteen dollars wrong?
%
There is a discount of 25% off on a $60 pair of shoes. How much are the shoes?
$45
d. Why is forty-five dollars correct?
$60x .25300
120$15.00
$60- 15$45
A shirt cost $30 plus 7% tax. What is the total cost?
$32.10
d. Why is thirty-two dollars and ten cents correct?
$30x .07
$2.10
$30.00+ 2.10$32.10
