Absolute Value and Integers

Algebra Seminar2012-2013

Integers less than zero Integers greater than zeroare negative integers are positive integers

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

negatives are zero is neither positives CAN written with negative nor be written a (-) sign positive with a (+) sign

Integers & Absolute Value

Writing Integers to describe each

Real-Life Situation

Example 1: an increase of 6 inches

Example 2: scored 10 fewer points

Example 3: a loss of 7 pounds

Example 4: earned 5 dollars interest

Example 5: a temperature of 9 degreesbelow zero

Integers & Absolute Value

Writing Integers to describe each

Real-Life Situation

Example 1: an increase of 6 inches → + 6

Example 2: scored 10 fewer points → - 10

Example 3: a loss of 7 pounds → - 7

Example 4: earned 5 dollars interest → + 5

Example 5: a temp of 9 degrees below zero → - 9

Integers & Absolute Value

What is absolute value?Definition: The distance of a number away from zero

on the number line

What does absolute value look like?

the absolute

value of 7 | 7 | = 7

the absolute

value of – 7 | – 7 | = 7

Integers & Absolute Value

What does absolute value look like on a number line?

7 units 7 units

-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8

Integers & Absolute Value

Evaluate the expression.

Example 1: | 3 |

Example 2: | - 68 |

Example 3: | 6 | + | - 9 |

Example 4: | - 8 | - | - 9 |

Absolute Value Practice

Evaluate 6 + | b | if b = - 16.

6 + | b | = 6 + | - 16 |

= 6 + 16

= 22

Evaluating Absolute Value

Integers & Absolute Value

Absolute Value in real life!An eyeglass prescription is given as a positive or

negative number. A prescription for a person who is farsighted is positive. A prescription for a person who is nearsighted is negative. The greater absolute value, the stronger the prescription. Which prescription is stronger, -3 or 2?

Step 1: Think about the problem. What information was given and what am I trying to figure out?

Integers & Absolute Value

Absolute Value in real life!An eyeglass prescription is given as a positive or

negative number. A prescription for a person who is farsighted (can’t see near) is positive. A prescription for a person who is nearsighted is negative. The greater absolute value, the stronger the prescription. Which prescription is stronger, -3 or 2?

Step 2: Determine the answer

What is the absolute value of each prescription?

| -3 | | 2 |

3 2

Which prescription is greater?

-3!

Absolute Value in real life!

A seagull is flying at an altitude of 107 feet and a shark is swimming at a depth of 112 feet relative to sea level. Which animal is farther from sea level?

Sea level (0 feet)

107 feet

-112 feet