1. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers NS1.2 multiply rational numbers (integers, fractions, and terminating decimals) California Standards

2. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Notes

3. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers 1(6) 8(7) = Multiply. Write the answer in simplest form. 6767 Simplify. 3 28 = 1818 = 1(6) 8(7) Multiply numerators. Multiply denominators. Look for common factors: 2. 3 4 Additional Example 1A: Multiplying Fractions Notes

4. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers –2(9) 3(2) = 3 1 Simplify. –3 = Look for common factors: 2, 3. 1212 2323 – 1 – 1 Additional Example 1B: Multiplying Fractions Multiply. Write the answer in simplest form. 4 Write 4 as an improper fraction. 1212 1212 2323 – 4 9292 2323 – = Notes

5. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers 3(5) 5(8) = Multiply. Write the answer in simplest form. 5858 Simplify. 3838 = 3535 Look for common factors: 5. 1 1 Check It Out! Example 1A Elbow Partners

6. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers –7(4) 8(7) = = 1 2 Simplify. Multiply numerators. Multiply denominators. Look for common factors: 4, 7. 4747 7878 – 1 –1–1 1212 = – Multiply. Write the answer in simplest form. Check It Out! Example 1B Face Partners

7. 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. Notes Ex. 4/5 * 8 = 4 * 8 = 32 = 6 2/5 5 * 1 5

8. 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. 1 20 Additional Example 2: Application = (7) = 1 20 Multiply numerators and denominators. 1 20 7171 1 7 20 1 = 7 20 Joy completes of her painting in a 7-day week. 7 20 Notes

9. 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. 1717 Check It Out! Example 2 = (5) = 1717 Multiply numerators and denominators. 1717 5151 1 5 I7 1 = 5757 Mark runs mile in 5 days. 5757 Face Partner

10. 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.

11. 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) 1.500  –0.51 2 decimal places –1.02 0 + 2 = 2 decimal places. 2 decimal places 1 decimal place 2 + 1 = 3 decimal places or 1.5 Notes

12. Evaluating Algebraic Expressions 2-4 Multiplying Rational Numbers Multiply. 1 decimal place3.1 B. (–0.4)(–2.53) –0.4  –2.53 Check It Out! Example 3 A. 3.1(0.28) 1.012  0.28 2 decimal places 0.868 1 + 2 = 3 decimal places 1 decimal place 2 decimal places 1 + 2 = 3 decimal places Rally Coach