035 lesson 23
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The document discusses the rules for multiplying integers. It states that if two integers have the same sign, their product is positive, and if they have opposite signs, their product is negative. It also notes that if one or both integers being multiplied is 0, the product is 0. Examples are provided to illustrate multiplying integers with the same sign, opposite signs, and where one factor is 0. The rules are then generalized to multiplying more than two integers. An example problem demonstrates multiplying several integers together and determining the sign of the product based on the number of negative factors.
035 lesson 23
- 1. Lesson 23<br />MULTIPLICATION OF INTEGERS<br />Objectives<br />After this lesson, the students are expected to:<br />discuss how to multiply integers;<br />master the rules in multiplying integers;<br />analyze the given expression.<br />249884371<br />To multiply a pair of integers if both numbers have the same sign, their product is the product of their absolute values (their product is positive). If the numbers have opposite signs, their product is the opposite of the product of their absolute values (their product is negative). If one or both of the integers is 0, the product is 0. <br />Examples: In the product below, both numbers are positive, so we just take their product.4 × 3 = 12 In the product below, both numbers are negative, so we take the product of their absolute values.(-4) × (-5) = |-4| × |-5| = 4 × 5 = 20 In the product of (-7) × 6, the first number is negative and the second is positive, so we take the product of their absolute values, which is |-7| × |6| = 7 × 6 = 42, and give this result a negative sign: -42, so (-7) × 6 = -42. In the product of 12 × (-2), the first number is positive and the second is negative, so we take the product of their absolute values, which is |12| × |-2| = 12 × 2 = 24, and give this result a negative sign: -24, so 12 × (-2) = -24. <br />47625033655<br />To multiply any number of integers:<br />1. Count the number of negative numbers in the product. <br />2. Take the product of their absolute values.<br />3. If the number of negative integers counted in step 1 is even, the product is just the product from step 2, if the number of negative integers is odd, the product is the opposite of the product in step 2 (give the product in step 2 a negative sign). If any of the integers in the product is 0, the product is 0.<br />Example:<br />44426082773874 × (-2) × 3 × (-11) × (-5) = ?<br />Counting the number of negative integers in the product, we see that there are 3 negative integers: -2, -11, and -5. Next, we take the product of the absolute values of each number:4 × |-2| × 3 × |-11| × |-5| = 1320. Since there were an odd number of integers, the product is the opposite of 1320, which is -1320, so4 × (-2) × 3 × (-11) × (-5) = -1320.<br />4442608149448<br />-579233-329712WORKSHEET NO. 23<br />NAME: ___________________________________DATE: _____________ <br />YEAR & SECTION: ________________________RATING: ___________<br />-9144026670<br /> Solve the following<br />SOLUTION-2344x-65=_______________________<br />5423x(-7)= _______________________<br />56x(-67)= ________________________<br />-576x(-67)= _______________________<br />-4322128321946-54x7=___________________________<br />768x(-753)= ______________________<br />-432x(-67)= _______________________<br />754x(-67)= _______________________<br />123x(-664)= ______________________<br />6788x(-7)= _______________________<br />12x(43)(-8)= ______________________<br />54x(-65)(5)= ______________________<br />56x8(-78)= _______________________<br />45x(-65)(45)= _____________________<br />56x(-97)(45)= _____________________<br />