MATH 2.4 : Multiplication & Division of Integers

• The product of two integers with the same sign is always a positive integer
• The product of two integers with different signs is always a negative integer.
• Perform the indicated operations: (−7) × (−4) ÷ (−2).

  Solution

  Perform multiplication and division from left to right.

  Step 1: Multiply first: (−7) × (−4)

  Since the factors have the same sign, the product must be positive.

  (−7) × (−4) = +28 or 28

  Step 2: Divide 28 by −2.

  Since the dividend and the divisor have different signs, the quotient must be

  negative.

  28 ÷ (−2) = −14

  Therefore, (−7) × (−4) ÷ (−2) = −𝟏𝟒.
• What is the first step to calculate the average temperature?

  Write an expression for the average.
• How is the average temperature calculated for five days?

  By getting the total temperature for five days and dividing by the total number of days.
• What is the expression used to calculate the average temperature in this example?

  average = \(\frac{(-5) + 3 \times (-6) + (-7)}{5}\)
• How is a temperature of -6°C for three days expressed in the average calculation?

  As \(3 \times (-6)\).
• What operation is performed first according to the order of operations in this calculation?

  Multiplication.
• What is the average temperature after performing the multiplication in the expression?

  average = \(\frac{(-5) + (-18) + (-7)}{5}\)
• What is the result of adding \((-5) + (-18) + (-7)\)?

  • 30.
• What is the final step to find the average temperature after summing the integers?

  Divide the sum by the total number of days.
• What sign does the average temperature take when the numbers have different signs?

  The answer should be negative.
• What is the average temperature of this town in Russia over the five days?

  • 6°C.