Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Chapter 2 Integers and Introduction to Variables

Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. 2.2 Introduction to Integers

33 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Definitions Positive Numbers: Numbers greater than 0. Negative Numbers: Numbers that are less than 0.

44 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Example A worker in a silver mine in Nevada works 1445 feet underground. Write this as a signed number feet underground = –1445

55 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Graphing Integers EXAMPLE Graph the following integers on a number line:

66 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Comparing Integers 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. Also recall that the symbol > means “is greater than” and the symbol < means “is less than”.

77 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Example Insert between each pair of numbers to make a true statement. a. −6 ____ 3 b. c. < > >

88 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Absolute Value The absolute value of a number is the number’s distance from 0 on a number line. The symbol for absolute value is | |. Example: Find each absolute value. a. b. c.

99 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Finding the Opposite of a Number Two numbers that are the same distance from 0 on the number line but are on opposite sides of 0.

10 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Example Find the opposite of each number. a. 11 b. ‒ 8c. 0 a. The opposite of 11 is ‒ 11. b. The opposite of ‒ 8 is 8. c. The opposite of 0 is 0.

11 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Example Simplify. a. −(−9) = 9 b. c.

12 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Reading Bar Graphs Containing IntegersEXAMPLE Which planet has the lowest average temperature? Neptune

13 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall. Example According to the bar graph, which planet has the third lowest average temperature? The bar with the third lowest temperature is Saturn with a lowest average temperature of