1. Multiply and Divide Real Numbers Honors Math – Grade 8

2. What operation? Get ready for the Lesson A diver descended into the ocean at a rate of 2.1 meters per minute over a 3-minute period. What signed number represents the diver’s final depth at the end of the 3 minutes? Multiplication Remember that multiplication is a shortcut for repeated addition. Think… What is the sign of the sum of -2.1 + (-2.1) + (-2.1)? KEY CONCEPT Multiplying Signed Numbers 1.If the factors have like signs, the product is positive! 2.If the factors have unlike signs, the product is negative!

3. Simplify the absolute values. Rename the mixed numbers as improper fractions. Cancel where possible. Multiply and rename. The factors have like signs. The product is positive! Multiply the absolute value of the numbers.

4. Simplify the absolute values. Rename the mixed numbers as improper fractions. Cancel if possible. Multiply and rename. The factors have unlike signs. The product is negative! Multiply the absolute value of the numbers.

5. Simplify the absolute values. Remember to align the digits when multiplying decimals! Determine the number of decimal places in the product. Place the decimal point in the product. The factors have unlike signs. The product is negative! Multiply the absolute value of the numbers.

6. KEY CONCEPT Dividing Signed Numbers 1.If the dividend and divisor have like signs, the product is positive! 2.If the dividend and divisor have unlike signs, the product is negative! Remember a fraction bar is a division symbol. Divide the absolute value of the numbers. Simplify the absolute values. Move the decimal point in the divisor and the dividend. Divide. The dividend and the divisor have like signs. The quotient is positive!

7. Divide the absolute value of the numbers. Simplify the absolute values. Move the decimal point in the divisor and the dividend. Divide. The dividend and the divisor have unlike signs. The quotient is negative!

8. Divide the absolute value of the numbers. Simplify the absolute values. Change any mixed numbers to improper fractions. Remember, when dividing fractions, you must multiply by the reciprocal of the divisor! The dividend and the divisor have like signs. The quotient is positive! Cancel and multiply.