LESSON 2 2 Identifying Opposites and Absolute Value

LESSON 2. 2 Identifying Opposites and Absolute Value of Rational Numbers How can you identify opposites and absolute values of rational numbers?

Texas Essential Knowledge and Skills The student is expected to: Number and operations— 6. 2. B Identify a number, its opposite, and its absolute value. Mathematical Processes 6. 1. D Communicate mathematical ideas, reasoning, and their implications using multiple representations, including symbols, diagrams, graphs, and language as appropriate.

ADDITIONAL EXAMPLE 1 Alberto’s average running time for 100 meters is sec. Each day after he warms up, Alberto records his run time so he can compare it to his average time.

ADDITIONAL EXAMPLE 1 Graph the change in time for Tuesday and its opposite.

ADDITIONAL EXAMPLE 2 Eric tries to begin each day with $5. 00 in his backpack. The table shows how much more or less than $5. 00 he had in his backpack at the end of each day during a 3 -day period.

ADDITIONAL EXAMPLE 2 Graph the amount more or less than $5 he had at the end of Tuesday.

2. 2 LESSON QUIZ 6. 2. B 1. The table shows how the rainfall varied each of three months compared with the average rainfall for that month.

a. Graph each month’s rainfall variation and its opposite on a number line.

b. For which month did the variation differ the most from the monthly average? Explain. July; because July had 3. 25 more inches than the average June had about 1 inch less than average, and August had 0. 5 inches less than average.

Write the absolute value of each number. 2. 9. 01 3. 4. – 8. 7 5. 8. 7

On Monday morning the opening price of a stock was $10. Complete the table to find the closing price of the stock on Friday afternoon. What was the closing price? The closing price on Friday was $11. 75.

How can you identify opposites and absolute values of rational numbers? Opposites are the same distance from 0 on the number line but on different sides of 0. Absolute value is the number’s distance from 0.