Course Adding and Subtracting Rational Numbers Warm Up Simplify Write each decimal as a fraction in simplest form – – 11 50

Course Adding and Subtracting Rational Numbers Problem of the Day Four sprinters run a race. In how many different ways can they arrive at the finish line, assuming there are no ties? 24

Course Adding and Subtracting Rational Numbers Learn to add and subtract decimals and rational numbers with like denominators. TB P

Course Adding and Subtracting Rational Numbers In August 2001, at the World University Games in Beijing, China, Jimyria Hicks ran the 200-meter dash in seconds. Her best time at the U.S. Senior National Meet in June of the same year was seconds. How much faster did she run in June? She ran 0.73 second faster in June – Write the numbers so that the decimals line up. Additional Example 1: Sports Application

Course Adding and Subtracting Rational Numbers (–1.2) Move right 0.3 units. 0.4 –1.0 –0.40 From 0.3, move left 1.2 units. – Use a number line to find the sum. Additional Example 2A: Using a Number Line to Add Rational Decimals –1.4 You finish at – 0.9, so (–1.2) = –0.9.

Course Adding and Subtracting Rational Numbers Use a number line to find the sum. Additional Example 2B: Using a Number Line to Add Rational Decimals Move right units You finish at, so = From, move right units

Course Adding and Subtracting Rational Numbers ADDING AND SUBTRACTING WITH LIKE DENOMINATORS Words Numbers To add or subtract rational numbers with the same denominator, add or subtract the numerators and keep the denominator. =, or – – – = 1 + (–4)

Course Adding and Subtracting Rational Numbers ADDING AND SUBTRACTING WITH LIKE DENOMINATORS Words Algebra To add or subtract rational numbers with the same denominator, add or subtract the numerators and keep the denominator. = + adad a + b d bdbd

Course Adding and Subtracting Rational Numbers Remember! Subtracting a number is the same as adding its opposite. SMATO! Subtract Means Add The Opposite

Course Adding and Subtracting Rational Numbers Additional Example 3: Adding and Subtracting Fractions with Like Denominators Subtract numerators. Keep the denominator –– –– 5959 = – 7979 = – 3737 –2 – 5 9 = 6 + (–3) 7 = can be written as. – 3737 –3 7 Add or subtract. Write each answer in simplest form –3 7 A. B.

Course Adding and Subtracting Rational Numbers 12.1 – x for x = –0.1 Substitute –0.1 for x – (–0.1) 12.2 Think: 12.1 – (–0.1) = Evaluate the expression for the given value of the variable. Additional Example 4A: Evaluating Expressions with Rational Numbers

Course Adding and Subtracting Rational Numbers 4545 = Add numerators, keep the denominator Simplify. + m for m = = Substitute 3 for m (10) = = Evaluate the expression for the given value of the variable. Additional Example 4B: Evaluating Expressions with Rational Numbers

Course Adding and Subtracting Rational Numbers Add or subtract. 1. – (–2.8) 7.2 – x for x = – – – – 64.9 Lesson Quiz: Part 1 Evaluate.

Course Adding and Subtracting Rational Numbers Sarah’s best broad jump is 1.6 meters, and Jill’s best is 1.47 meters. How much farther can Sarah jump than Jill? Lesson Quiz: Part m