Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Warm Up Write each number as an improper fraction

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Warm Up Hanna and Elizabeth drove to Niagara Falls for vacation. Hannah drove miles and Elizabeth drove miles. How far did they drive together?

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers 1(6) 8(7) = Multiply. Write the answer in simplest form Simplify = 1818 = 1(6) 8(7) Multiply numerators. Multiply denominators. Look for common factors: Additional Example 1A: Multiplying Fractions

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers –2(9) 3(2) = = 3 1 Simplify. –3 = Multiply numerators. Multiply denominators. Look for common factors: 2, – 1 – 1 Additional Example 1B: Multiplying Fractions Multiply. Write the answer in simplest form. 4 Write 4 as an improper fraction – – =

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers 3(5) 5(8) = Multiply. Write the answer in simplest form Simplify = 3535 = 3(5) 5(8) Multiply numerators. Multiply denominators. Look for common factors: Partner Share! Example 1A

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers –7(4) 8(7) = = 1 2 Simplify. Multiply numerators. Multiply denominators. Look for common factors: 4, – 1 –1– = – Multiply. Write the answer in simplest form. Partner Share! Example 1B

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers To multiply a fraction by an integer, first write the integer as a fraction with a denominator of 1. Then multiply as you would with two fractions.

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Joy completes of her painting each day. How much of her painting does she complete in a 7 day week? Write the integer 7 as a fraction Additional Example 2: Application = (7) = 1 20 Multiply numerators and denominators = 7 20 Joy completes of her painting in a 7-day week. 7 20

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Mark runs mile each day. What is the total distance Mark runs in 5 days? Write the integer 5 as a fraction Partner Share! Example 2 = (5) = 1717 Multiply numerators and denominators I7 1 = 5757 Mark runs mile in 5 days. 5757

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers To multiply decimals, first multiply as you would with integers. The number of decimal places in the product is equal to the sum of the number of decimal places in the factors.

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Multiply. 0 decimal places2 B. (–0.4)(–3.75) –3.75  0.4 Additional Example 3: Multiplying Decimals A. 2(–0.51)  – decimal places – = 2 decimal places. 2 decimal places 1 decimal place = 3 decimal places or 1.5

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Multiply. 1 decimal place3.1 B. (–0.4)(–2.53) –0.4  –2.53 Partner Share! Example 3 A. 3.1(0.28)  decimal places = 3 decimal places 1 decimal place 2 decimal places = 3 decimal places

Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers 4. Evaluate 2 (x) for x =. 1. Lesson Review! Multiply. – – –0.47(2.2) – Edgar runs mile each day. What is the total distance that Edgar runs in a 7-day week? miles 2929