Multiply & Divide Integers Honors Math – Grade 6

Rectangle Multiplication of Integers PROBLEM OF THE DAY The mercury in the barometer fell 3 cm per hour during the 4 hours before the storm struck. What integer represents the mercury-level change during those 4 hours? What important facts are given? To find the change in mercury, multiply 4 and -3. Let’s take a closer look and use the area of a rectangle to multiply integers. Rectangle Multiplication of Integers The change in the number of centimeters of mercury is -12.

The product of two integers with like signs is positive. KEY CONCEPT Multiply Integers The product of two integers with like signs is positive. positive x positive = positive negative x negative = positive The product of two integers with unlike signs is negative. positive x negative = negative negative x positive = negative

Patterns can be used to find products of more than two negative factors. Odd Number of Factors Even Number of Factors KEY CONCEPT Multiplication Patterns When the number of negative factors is EVEN, the product is POSITIVE. When the number of negative factors is ODD, the product is NEGATIVE.

Tell whether each product is positive or negative, then find the product.

Find each product.

Multiplication Sentence Related Division Sentence Multiplication and Division are inverse operations. One undoes the other. Let’s take a look at this relationship to determine the rules for dividing integers. Multiplication Sentence Related Division Sentence The pattern above shows that the rules for dividing integers are similar to the rules for multiplying integers. Remember, since a number cannot be divided by zero, division by zero is said to be undefined.

The quotient of two integers with like signs is positive. KEY CONCEPT Dividing Integers The quotient of two integers with like signs is positive. The quotient of two integers with unlike signs is negative.

There are special rules for division that involves -1, 0 and 1…