Multiplying Real Numbers

Products of Positives and Negatives

Rules for Multiplying Non zero Numbers

• DO THE MATH!!!!!!• Write down the numerical quantity THEN• Count the negative signs

– If the number of signs used was odd: – The answer is NEGATIVE!– If the number of signs used was even: – The answer is POSITIVE!

2(-3)(4)(-2) Think!

23 4 2 is 48 and there are TWO negative signs so the answer is POSITIVE 48

2(-3)(-4)(-2) Think!23 4 2 is 48 and there are THREE negative signs so the answer is NEGATIVE 48

Now you try!• 3(-5)

• -2(4)(5)

• -1/2(-2)(3)

• (-2)3

• -(-3)3

Products in real life

• Displacement is a measure of the distance covered with the direction in which the object traveled!

• Example: If I fell off a cliff at a velocity of -5 feet per second, what would my displacement be?

Now you try!

• A helicopter has a velocity of -15 feet per second. Find the displacement after 4.5 seconds.

• Bonus: What is the DISTANCE traveled in 10 seconds?

Products of variable terms

• Remember when multiplying variable terms (AKA Simplifying expressions)

1. Multiply coefficients first2. Then multiply variables (getting the

exponents right!)3. Add up the negative signs and write the

answer!(-2) (x)(x)(-4x)

Your turn again!

• 8(-t)

• -x (-x)(-x)(-x)

• -7(-b)3

BE CAREFUL! The last problem is TRICKY!!!!!

Individual Practice

• PWB Section 2.5• HW pg. 97 41-55• Where are you in chapter 2????• Vocabulary is due Sept 15!!!!• 1: What chapter are we doing again?• 5: I better beg my folks to bring me to tutoring!• 10: I will have a high grade on Friday’s quiz!