Place Value and Names for Numbers

1. Section 1.2 Place Value and Names for Numbers

2. Hundred-billions Ten-billions Billions Hundred-millions Ten-millions Millions Hundred-thousands Ten-thousands Thousands Hundreds Tens Ones 3 5 6 8 9 4 0 2 The position of each digit in a number determines its place value. Martin-Gay, Prealgebra, 5ed

3. Billions Millions Thousands Ones Hundred-billions Ten-billions Billions Hundred-millions Ten-millions Millions Hundred-thousands Ten-thousands Thousands Hundreds Tens Ones 3 5 6 8 9 4 0 2 A whole number such as 35,689,402 is written in standard form. The columns separate the digits into groups of threes. Each group of three digits is a period. Martin-Gay, Prealgebra, 5ed

4. Hundred-billions Ten-billions Billions Hundred-millions Ten-millions Millions Hundred-thousands Ten-thousands Thousands Hundreds Tens Ones 3 5 6 8 9 4 0 2 To write a whole number in words, write the number in each period followed by the name of the period. thirty-five million, six hundred eighty-nine thousand, four hundred two

5. Helpful Hint The name of the ones period is not used when reading and writing whole numbers. Also, the word “and” is not used when reading and writing whole numbers. It is used when reading and writing mixed numbers and some decimal values as shown later. Martin-Gay, Prealgebra, 5ed

6. Standard Form Expanded Form 4,786 = 4000 + 700 + 80 + 6 The place value of a digit can be used to write a number in expanded form. The expanded form of a number shows each digit of the number with its place value. Martin-Gay, Prealgebra, 5ed

7. Comparing Whole Numbers We can picture whole numbers as equally spaced points on a line called the number line. 0 1 2 3 4 5 A whole number is graphed by placing a dot on the number line. The graph of 4 is shown. Martin-Gay, Prealgebra, 5ed

8. 0 1 2 3 4 5 Comparing Numbers . . . For any two numbers graphed on a number line, the number to the right is the greater number, and the number to the left is the smaller number. 2 is to the left of 5, so 2 is less than 5 5 is to the right of 2, so 5 is greater than 2 Martin-Gay, Prealgebra, 5ed

9. Comparing Numbers . . . 2 is less than 5 can be written in symbols as 2 < 5 5 is greater than 2 is written as 5 > 2 Martin-Gay, Prealgebra, 5ed

10. Helpful Hint One way to remember the meaning of the inequality symbols < and > is to think of them as arrowheads “pointing” toward the smaller number. For example, 2 < 5 and 5 > 2 are both true statements. Martin-Gay, Prealgebra, 5ed

11. Reading Tables Germany Russia Norway USA Austria Most Medals Olympic Winter (1924 – 2002) Games Source: The Sydney Morning Herald Flags courtesy of www.theodora.com/flags used with permission