percents 07/27/12lntaylor ©. table of contents learning objectives straight percent change in...

Percents

07/27/12 lntaylor ©

Table of Contents

Learning Objectives

Straight Percent

Change in Percent

Percent/Fraction/Decimal Equivalents Table

Practice

07/27/12 lntaylor ©

LO1:

LO2:

Define and differentiate fraction, percent and decimal equivalents

Memorize the Equivalents chart

07/27/12 lntaylor ©TOC

Learning Objectives

Def1:

Def2:

Fraction is a rational number that represent part of a whole(2/7 means 2 out of 7 total)

Decimal equivalent represents a number between -1 < 0 < 1(- 0.25 is the same as – ¼; 0.50 is the same as ½)


Definitions

Def3: Percent is a number followed by a % that represents theIncrease or decrease between two numbers100% increase would mean the beginning number doubled50% decrease means the beginning number reduced by half

PK1: Knowledge of fractions and decimals


Previous Knowledge


Straight Percent

Step1:

Step2:

You absolutely must carefully read & understand percent questionsbefore you start the problem!!!!!!

You have two choices of where to start this problem (3 or 6)Only one will give you the correct answer!


3 is what percent of 6?

Step3: Hint: Look for the number following the word “of”That number is the denominatorThe other number is the numerator

Step4: Convert the fraction to a decimal equivalentEquivalent means the fraction and decimal are exactly the same numberEven if they do not look the same

Step5: Covert decimal to percent by moving the decimal 2 places to the right

_63

3 1 6 2

0.50 = 50%

of 63

= = 0.50

Now you try



Step1:

Step2:








__40

5

5 1 40 8

0.125 = 12.5%

of 405

= = 0.125

Now you try



Step1:

Step2:








__ 5

40

40 8 5 1

8.0 = 800%

of 540

= = 8.0

Step1:

Step2:




What number is 75 percent of 12?

Step3: Hint: Look for the number following the word “of”That number is the denominator“What number” becomes the numerator ( x )

Step4: Convert the percent to a fractionThis means the same as 75/100 and reducingConverting decimals to fractions is easy – the denominator is always 100

Step5: Solve for xIt helps to double check your work!

__12 x

3 (12)4

x = 36/4

of 12What number

x =

=

34

x = 9

912

= ¾ or 75%75%

Now you try

What number is twenty percent of 50?


Step1:

Step2:




What number is twenty percent of 50?


Step4: Convert the percent to a fractionThis means the same as 20/100 and reducingConverting decimals to fractions is easy – the denominator is always 100


__50 x

1 (50)5

x = 50/5

of 50What number

x =

=

20100

x = 10

1050

= 1/5 or 20%20%

Now you try

What number is 34% of 200?


Step1:

Step2:






Step4: Convert the percent to a fractionThis means the same as 34/100 and you do not always have to reduce right hereConverting decimals to fractions is easy – the denominator is always 100


___200 x

34 (200)100

x = 34(2)

of 200What number

x =

=

34100

x = 68

68200 = 34/100 or 34%34%


Change in Percent

Step1:

Step2:


You have one choice of where to start this problem


Tim starts with 120 balloons. He had 80 left after he gave some to Mary. What percent did he give away?

Step3: Hint: the parts of percent change are;StartFinishSome number(s) in between

Step4: The beginning is always the denominator (120)Make sure you understand what they wantIt could be what is left OR what was given away

Step5: Covert fraction to a decimal to a percent

80starts with 120

120 – 80 = 40

___120

40

give away

= =13

0.33 = 33%

Now you try

Mark had 90 apples. After he gave away 30 what percent did he have left?


Step1:

Step2:




Mark had 90 apples. After he gave away 30 what percent did he have left?

Step3: Hint: the parts of percent change are:StartSome number(s) in betweenFinish



30had 90

90 – 30 =

___ 90

60

gave away

= =23

0.667 = 66.7%

60

Now you try

Rick had half as many marbles as John. John had 500 marbles.They each gave away 125 marbles. What percent did they have left?


Step1:

Step2:




Rick had half as many marbles as John. John had 500 marbles.They each gave away 125 marbles. What percent did they have left?

Step3: Hint: the parts of percent change are:StartSome number(s) in betweenMore numbers in betweenEnding



They each gave away 125500

500 + ½ (500) = 500 + 250 = 750 Beginning

half as many marbles as John

125 + 125 = 250 gave away 750 beginning- 250 gave away 500 left

___750

500= =

23

0.667 = 66.7%


Equivalents Table


Fraction Decimal Percent

1/2

1/3

1/4

1/5

1/6

1/7

1/8

1/9

1/10

> 0.50

>

>

>

>

>

0.33

0.25

0.20

0.16

0.14

> 0.125

> 0.11

> 0.10

>

>

>

>

>

>

>

>

>

50%

33%

25%

20%

16%

14%

12.5%

11.0

10%

clear answers


Practice


Problem Answer



30 is 60% of what number?



21 is 70% of what number?

What is the decimal equivalent of 3/8?

What is the decimal equivalent of 5/9

What is the decimal equivalent of 4 and 3/5?

> 50%

>

>

>

>

>

15

50 (30/x = .6)

900%

75

30

> 0.375 (3 x 0.125)

> 0.555 (5 x .111)

> 4.6 ( 4 + 3(.2))

clear answers

percents 07/27/12lntaylor ©. table of contents learning objectives straight percent change in...

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