2 4 Multiplying Rational Numbers Warm Up Write

2 -4 Multiplying Rational Numbers Warm Up Write each number as an improper fraction. 1. 2 1 3 7 3 2. 1 7 8 15 8 4. 6 2 3 20 3 5. 5 3 8 43 8 3. 3 2 17 5 5

2 -4 Multiplying Rational Numbers

2 -4 Multiplying Rational Numbers Example 1: Multiplying a Fraction and an Integer Multiply. Write the answer in simplest form. 6 A. – 8 7 – 8 • 6 7 – 48 Multiply. 7 6 – 6 Simplify. 7 Helpful Hint To write – 48 7 as a mixed number, divide: – 48 7 = – 6 R 6 = – 6 6 7

2 -4 Multiplying Rational Numbers Example 1: Multiplying a Fraction and an Integer Multiply. Write the answer in simplest form. B. 2 51 3 2 16 3 32 3 10 1 53 5(3) + 1 = 3 Multiply. 2 3 Simplify. = 16 3

2 -4 Multiplying Rational Numbers Check It Out: Example 1 Multiply. Write the answer in simplest form. A. 5 – 3 8 – 3 • 5 8 – 15 8 7 – 1 8 Multiply. Simplify.

2 -4 Multiplying Rational Numbers Check It Out: Example 1 Multiply. Write the answer in simplest form. B. 4 9 2 5 47 4 5 2 9(5) + 2 47 9 = = 5 5 5 188 5 Multiply. 3 5 Simplify. 37

2 -4 Multiplying Rational Numbers Example 2: Multiplying Fractions Multiply. Write the answer in simplest form. A. 1 6 8 7 1(6) 8(7) Multiply numerators. Multiply denominators. 3 1(6) 8(7) Look for common factors: 2. 3 28 Simplify. 4

2 -4 Multiplying Rational Numbers Example 2: Multiplying Fractions Multiply. Write the answer in simplest form. B. 2 9 – 3 2 – 2(9) 3(2) – 1 3 – 2(9) 3(2) 1 – 3 Multiply numerators. Multiply denominators. Look for common factors: 2, 3. 1 Simplify.

2 -4 Multiplying Rational Numbers Check It Out: Example 2 Multiply. Write the answer in simplest form. A. 3 5 5 8 3(5) 5(8) Multiply numerators. Multiply denominators. 1 1 3(5) 5(8) Look for common factors: 5. 3 8 Simplify.

2 -4 Multiplying Rational Numbers Check It Out: Example 2 Multiply. Write the answer in simplest form. B. – 7 4 8 7 – 7(4) 8(7) – 1 1 – 7(4) 8(7) 2 1 – 2 Multiply numerators. Multiply denominators. Look for common factors: 4, 7. 1 Simplify.

2 -4 Multiplying Rational Numbers Example 3: Multiplying Decimals Multiply. A. 2(– 0. 51) 2 • (– 0. 51) = – 1. 02 B. (– 0. 4)(– 3. 75) (– 0. 4) • (– 3. 75) = 1. 500 = 1. 5 00 Product is negative with 2 decimal places. Product is positive with 3 decimal places. You can drop the zeros after the decimal point.

2 -4 Multiplying Rational Numbers Check It Out: Example 3 Multiply. A. 3. 1 (0. 28) 3. 1 • (0. 28) = 0. 868 Product is positive with 3 decimal places. B. (– 0. 4)(– 2. 53) (– 0. 4) • (– 2. 53) = 1. 012 Product is positive with 3 decimal places.

2 -4 Multiplying Rational Numbers Example 4: Application Joy completes 1 of her painting each day. 20 How much of her painting does she complete in a 7 day week? 1 1 7 (7) = 20 20 1 1 • 7 = 20 • 1 Write as an improper fraction. Multiply. 7 = 20 7 Joy completes of her painting in a 7 -day week. 20

2 -4 Multiplying Rational Numbers Check It Out: Example 4 1 Mark runs mile each day. What is the total 7 distance Mark runs in a 5 -day week? 1 1 5 (5) = 7 7 1 1 = I 7 • • 5 1 Write as an improper fraction. Multiply. 5 = 7 5 Mark runs mile in a 7 -day week. 7

2 -4 Multiplying Rational Numbers Lesson Quiz Multiply. 1. 9 1 7 12 7 2. 2 – 5 3 8 – 5 3. – 0. 47(2. 2) – 1. 034 1 4 4. Evaluate 2 2 (x) for x =. 5 12 2 2 6 miles 9 8 5. Edgar runs 9 mile each day. What is the total distance that Edgar runs in a 7 -day week?