Percents 07/27/12lntaylor ©

Table of Contents Learning Objectives Straight Percent Change in Percent Percent/Fraction/Decimal Equivalents Table Practice 07/27/12lntaylor ©

LO1: LO2: Define and differentiate fraction, percent and decimal equivalents Memorize the Equivalents chart 07/27/12lntaylor © 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 ( is the same as – ¼; 0.50 is the same as ½) 07/27/12lntaylor © TOC Definitions Def3:Percent is a number followed by a % that represents the Increase or decrease between two numbers 100% increase would mean the beginning number doubled 50% decrease means the beginning number reduced by half

PK1:Knowledge of fractions and decimals 07/27/12lntaylor © TOC Previous Knowledge

07/27/12lntaylor © TOC Straight Percent

Step1: Step2: You absolutely must carefully read & understand percent questions before 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! 07/27/12lntaylor © TOC 3 is what percent of 6? Step3:Hint: Look for the number following the word “of” That number is the denominator The other number is the numerator Step4:Convert the fraction to a decimal equivalent Equivalent means the fraction and decimal are exactly the same number Even if they do not look the same Step5:Covert decimal to percent by moving the decimal 2 places to the right _6_ = 50% of6 3 = = 0.50

Now you try 5 is what percent of 40? 07/26/12lntaylor © TOC

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have two choices of where to start this problem (5 or 40) Only one will give you the correct answer! 07/27/12lntaylor © TOC 5 is what percent of 40? Step3:Hint: Look for the number following the word “of” That number is the denominator The other number is the numerator Step4:Convert the fraction to a decimal equivalent Equivalent means the fraction and decimal are exactly the same number Even if they do not look the same Step5:Covert decimal to percent by moving the decimal 2 places to the right __ = 12.5% of40 5 = = 0.125

Now you try 40 is what percent of 5? 07/26/12lntaylor © TOC

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have two choices of where to start this problem (40 or 5) Only one will give you the correct answer! 07/27/12lntaylor © TOC 40 is what percent of 5? Step3:Hint: Look for the number following the word “of” That number is the denominator The other number is the numerator Step4:Convert the fraction to a decimal equivalent Equivalent means the fraction and decimal are exactly the same number Even if they do not look the same Step5:Covert decimal to percent by moving the decimal 2 places to the right __ = 800% of5 40 = = 8.0

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have two choices of where to start this problem (75 or 12) Only one will give you the correct answer! 07/27/12lntaylor © TOC 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 fraction This means the same as 75/100 and reducing Converting decimals to fractions is easy – the denominator is always 100 Step5:Solve for x It helps to double check your work! __ 12 x 3 (12) 4 x = 36/4 of 12What number x = = 3434 x = = ¾ or 75%75%

Now you try What number is twenty percent of 50? 07/26/12lntaylor © TOC

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have two choices of where to start this problem (20 or 50) Only one will give you the correct answer! 07/27/12lntaylor © TOC What number is twenty percent of 50? 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 fraction This means the same as 20/100 and reducing Converting decimals to fractions is easy – the denominator is always 100 Step5:Solve for x It helps to double check your work! __ 50 x 1 (50) 5 x = 50/5 of 50 What number x = = x = = 1/5 or 20% 20%

Now you try What number is 34% of 200? 07/26/12lntaylor © TOC

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have two choices of where to start this problem (34 or 200) Only one will give you the correct answer! 07/27/12lntaylor © TOC What number is 34% of 200? 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 fraction This means the same as 34/100 and you do not always have to reduce right here Converting decimals to fractions is easy – the denominator is always 100 Step5:Solve for x It helps to double check your work! ___ 200 x 34 (200) 100 x = 34(2) of 200What number x = = x = = 34/100 or 34% 34%

07/27/12lntaylor © TOC Change in Percent

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have one choice of where to start this problem 07/27/12lntaylor © TOC 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; Start Finish Some number(s) in between Step4:The beginning is always the denominator (120) Make sure you understand what they want It could be what is left OR what was given away Step5:Covert fraction to a decimal to a percent 80 starts with – 80 = 40 ___ give away = = 33%

Now you try Mark had 90 apples. After he gave away 30 what percent did he have left? 07/26/12lntaylor © TOC

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have one choice of where to start this problem 07/27/12lntaylor © TOC Mark had 90 apples. After he gave away 30 what percent did he have left? Step3:Hint: the parts of percent change are: Start Some number(s) in between Finish Step4:The beginning is always the denominator (120) Make sure you understand what they want It could be what is left OR what was given away Step5:Covert fraction to a decimal to a percent 30 had – 30 = ___ gave away = = 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? 07/26/12lntaylor © TOC

Step1: Step2: You absolutely must carefully read & understand percent questions before you start the problem!!!!!! You have one choice of where to start this problem 07/27/12lntaylor © TOC 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: Start Some number(s) in between More numbers in between Ending Step4:The beginning is always the denominator (750) Make sure you understand what they want It could be what is left OR what was given away Step5:Covert fraction to a decimal to a percent They each gave away ½ (500) = = 750 Beginning half as many marbles as John = 250 gave away 750 beginning gave away 500 left ___ = = 66.7%

07/27/12lntaylor © TOC Equivalents Table

07/27/12lntaylor © TOC FractionDecimalPercent 1/2 1/3 1/4 1/5 1/6 1/7 1/8 1/9 1/10 > 0.50 > > > > > > > 0.11 > 0.10 > > > > > > > > > 50% 33% 25% 20% 16% 14% 12.5% % clear answers

07/27/12lntaylor © TOC Practice

07/27/12lntaylor © TOC ProblemAnswer 17 is what percent of 34? What number is 30% of 50? 30 is 60% of what number? 27 is what percent of 3? What number is 25% of 300? 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% > > > > > (30/x =.6) 900% > (3 x 0.125) > (5 x.111) > 4.6 ( 4 + 3(.2)) clear answers