Download (mult Integers) - Freshman

P 111 #16-27 all
Students will learn how to multiply and divide integers.
MULTIPLYING and DIVIDING Integers
a) Multiplying INTEGER MAN
b) GOOD GUY vs. BAD GUY
c) RULES
Students will learn how to multiply and divide integers.
Students will learn how to multiply and divide integers.
About ME!!
• Hello people! I'm going to tell you about myself. First of all I'm zero,
which isn't a positive or a negative. My friends are positives and
negatives though..let me tell you about them though.
• Multiplication - when you multiply integers with same sign, do
normal multiplication and the sign of the answer is positive 3 x 4 =
12
• When you multiply integers with opposite sign, do normal
multiplication and the sign of the answer is positive (-3) x (-4) = 12
• When you multiply integers with opposite signs, do normal
multiplication and the sign of the answer is negative 3 x (-4) = -12
(-3) x (4) = -12 -the rules in multiplication are the same rules applying
to division, except of course you have to change the sign to division.
And me well...im zero. Zero is never negative or positive so
yeah....Bye!
RULES
Multiplication and Division
Same sign = POSITIVE
Different sign = NEGATIVE
Students will learn how to multiply and divide integers.
Remember the Rules!!
To multiply decimal numbers:
•
•
•
•
•
Multiply the numbers just as if they were whole numbers.
Line up the numbers on the right - do not align the decimal points.
Starting on the right, multiply each digit in the top number by each digit in
the bottom number, just as with whole numbers.
Add the products.
Place the decimal point in the answer by starting at the right and moving a
number of places equal to the sum of the decimal places in both numbers
multiplied.
MULTIPLY DECIMALS
(0.075)(6.4)
-0.075
X 6.4
300
4500
4800 Notice there are four total numbers after the
decimal so you will need to move the decimal, 4
places to the left. Correct answer is .4800
Students will learn how to multiply rational numbers.
For more explanation on multiplying
fractions, click on this link
http://www.math.com/school/subject1/lessons/S1U4L4GL.html
1st way to solve is to multiply across the top and bottom, than reduce if possible!
 2  5  10 1

     
 5  8  40 4
2nd way to solve is cross reduce than multiply
 2  5   2  1   1  1  1
                 
 5  8   1  8   1  4  4
Students will learn how to multiply rational numbers.
(4.5)( 2.3)  10.35
5 6
30
3
1
  
 1
 1
3 7
27
27
9
Students will learn how to multiply and divide integers.
DIFFERENT and SAME SIGNS
5(6)  30
 4(1.6)  6.4
3 3
9
  
4 8
32
Students will learn how to multiply and divide integers.
SIMPLIFY ALGEBRAIC EXPRESSIONS
 4(9 x)  36 x
 2 x(3 y )  6 xy
 2(3x)  8 x  y  14 x  y
Students will learn how to multiply and divide integers.
Another Example
7(3 y  4)  3(2 x  y ) 
 21y  28  6 x  3 y 
 24 y  6 x  28
1st skim through this Site:
http://www.mathsisfun.com/algebra/substitution.html
2
m
3
a  2.7
b  3.9
 2   6  2   12 
6m  6               4
 3   1  3   3 
Students will learn how to multiply rational numbers.
a  2.7 b  3.9
Solve : ab  8 
(2.7)(3.9)  8 
 10.53  8 
 18.53
P 81 #16 – 38 EVENS
P82 #42 – 48 EVENS
E/C (ALL)
Students will learn how to multiply rational numbers.
POST THIS IN YOUR DISSCUSION
Tell me what you learned today.
What happens if you don’t know the
Integer Rules?
Students will learn how to multiply and divide integers.