Absolute Value and Integers Algebra Seminar 2012-2013

Integers & Absolute Value Integers less than zero Integers greater than zero are 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 degrees below 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 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

Absolute Value Practice Evaluate the expression. Example 1: | 3 | Example 2: | - 68 | Example 3: | 6 | + | - 9 | Example 4: | - 8 | - | - 9 |

Evaluating Absolute Value Evaluate 6 + | b | if b = - 16. 6 + | b | = 6 + | - 16 | = 6 + 16 = 22

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? 107 feet Sea level (0 feet) -112 feet