Basic Math & Pre-Algebra All-in-One For Dummies (+ Chapter Quizzes Online). Mark Zegarelli

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Basic Math & Pre-Algebra All-in-One For Dummies (+ Chapter Quizzes Online) - Mark  Zegarelli


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into 1,413 just 1 time. So this time, write 1 above the line after the 4, multiply math, and subtract:

math

      Therefore, math — that is, 741 with a remainder of 407.

      The Big Four Operations: Addition, Subtraction, Multiplication, and Division

      1  Chapter 3: Counting on Success: Numbers and Digits Knowing Your Place Value Close Enough for Rock ‘n’ Roll: Rounding and Estimating Practice Questions Answers and Explanations Whaddya Know? Chapter 3 Quiz Answers to Chapter 3 Quiz

      2  Chapter 4: Staying Positive with Negative Numbers Understanding Where Negative Numbers Come From Sign-Switching: Understanding Negation and Absolute Value Addition and Subtraction with Negative Numbers Knowing Signs of the Times (and Division) for Negative Numbers Practice Questions Answers and Explanations Whaddya Know? Chapter 4 Quiz Answers to Chapter 4 Quiz

      3  Chapter 5: Putting the Big Four Operations to Work Switching Things Up with Inverse Operations and the Commutative Property Getting with the In-Group: Parentheses and the Associative Property Understanding Inequalities Moving Beyond the Big Four: Exponents and Square Roots Practice Questions Answers and Explanations Whaddya Know? Chapter 5 Quiz Answers to Chapter 5 Quiz

      Counting on Success: Numbers and Digits

      IN THIS CHAPTER

       Bullet Understanding how place value turns digits into numbers

       Bullet Distinguishing whether zeros are important placeholders or meaningless leading zeros

       Bullet Reading and writing long numbers

       Bullet Understanding how to round numbers and estimate values

      When you’re counting, ten seems to be a natural stopping point — a nice, round number. The fact that our ten fingers match up so nicely with numbers may seem like a happy accident. But of course, it’s no accident at all. Fingers were the first calculator that humans possessed. Our number system — the Hindu-Arabic numbers, also called the decimal numbers — is based on the number ten because humans have 10 fingers instead of 8 or 12. In fact, the very word digit has two meanings: numerical symbol and finger.

      In this chapter, I show you how place value turns digits into numbers. I also show you when 0 is an important placeholder in a number and why leading zeros don’t change the value of a number. And I show you how to read and write long numbers. After that, I discuss two important skills: rounding numbers and estimating values.

      TELLING THE DIFFERENCE BETWEEN NUMBERS AND DIGITS

      Sometimes people confuse numbers and digits. For the record, here’s the difference:

       A digit is a single numerical symbol, from 0 to 9.

       A number is a string of one or more digits.

      For example, 7 is both a digit and a number. In fact, it’s a one-digit number. However, 15 is a string of two digits, so it’s a number — a two-digit number. And 426 is a three-digit number. You get the idea.

      The number system you’re most familiar with — Hindu-Arabic numbers — has ten familiar digits:

math

      Yet with only ten digits, you can express numbers as high as you care to go. In this section, I show you how it happens.

      Counting to ten and beyond

      The ten digits in our number system allow you to count from 0 to 9. All higher numbers are produced using place value. Place value assigns a digit a greater or lesser value, depending on where it appears in a number. Each place in a number is ten times greater than the place to its immediate right.

Millions Thousands
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