Idiot\'s Guides Basic Math and Pre-Algebra

Chapter 7: Ratios, Proportions, and Percentages 89 Changing ratios to percentages is like changing fractions to a common denomin ...

90 Part 1: The World of Numbers Let’s walk through some examples of the different types of problems. First, finding a percentage ...

Chapter 7: Ratios, Proportions, and Percentages 91 One last example before we move on. This one asks you to find the part. What ...

92 Part 1: The World of Numbers Calculating with Percentages ................................................................... ...

Chapter 7: Ratios, Proportions, and Percentages 93 The amount borrowed or invested is the principal, and the percent of that pri ...

94 Part 1: The World of Numbers Suppose you know that you need $2,000 to pay for a vacation three years from now, and you’d like ...

Chapter 7: Ratios, Proportions, and Percentages 95 When you go out shopping, you don’t always know exactly what the sales tax is ...

96 Part 1: The World of Numbers To find 15 or 20 percent quickly by mental math, remember that 10 percent of a number is one ten ...

Chapter 7: Ratios, Proportions, and Percentages 97 Let’s start with an example of a percent increase. Allison invests $800 in a ...

98 Part 1: The World of Numbers Ready to make sure you’ve got it? Here are some for you to try. CHECK POINT George invests $500 ...

PA RT 2 Into the Unknown It’s nice to take a world tour, even in the world of numbers, but sometimes it can be a scary trip. If ...

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CHAPTER 8 Variables and Expressions In This Chapter Writing expressions with variables Finding values for variables Multiplying ...

102 Part 2: Into the Unknown Using Variables A variable is any symbol that stands for a number. In algebra, the symbol is usuall ...

Chapter 8: Variables and Expressions 103 the 3 are connected by the conjunction +, and the verb, the action of the sentence, is ...

104 Part 2: Into the Unknown CHECK POINT Write each sentence using variables. The quotient of some number x and twelve is great ...

Chapter 8: Variables and Expressions 105 When you work with exponents, there are three basic rules to remember. Multiplication: ...

106 Part 2: Into the Unknown Dividing with Variables ........................................................................... ...

Chapter 8: Variables and Expressions 107 What if there’s a variable in the denominator? To divide^6 t^2 t , add your warning not ...

108 Part 2: Into the Unknown The toughest problems are the ones in which there is addition or subtraction in the denominator. Un ...