Transcript 3.6 Order of Ops

Pgs 137-142
What’s the answer?

6+4x4–3
Order of Operations

Hopefully you remember this:
 BEDMAS

Brackets, Exponents, Divide, Multiply,
Add, Subtract
B – Do the operations in brackets first
E – Next, evaluate any exponents
D
M Then, divide and multiply in order from left to right
A
Then, add and subtract in order from left to right
S
Brackets

Just be aware brackets can look like any
of these.
    
Exponents
This will be our next unit, so we will just
review the basics
 This is what you should know already:

Exponent
32
Base
Power
3 is the base
2 is the exponent
32 is the power
32 is a power of 3
Exponents
Remember that 32 means that we
have 3 units by 3 units
AKA 3 x 3 = 9

3
3
3 x 3 = 32
=9
9 is a square
number
Exponents
52 = 5 x 5 = 25

5
5
Watch your negatives

With rationals we have to be careful with
negative numbers.

With brackets
(-4)2 = (-4)(-4) = +16
If there are no brackets…
6   1 6  36
2
2
With decimals
2
(0.5)
= (0.5) x (0.5) = 0.25
B – Do the operations in brackets first
E – Next, evaluate any exponents
D
M Then, divide and multiply in order from left to right
A
Then, add and subtract in order from left to right
S
Example 1
(3.4  0.6)  4  0.2
2
 2.8  4  0.2
Brackets first.
2
 2.8  16  0.2
 2.8  3.2
 0.4
Then evaluate the power
Then multiply
Add
3 7  5 
    
 4 8   16 
Example 2
Subtract in the brackets first
Use a common denominator of 8
6 7  5 
    
 8 8   16 
 1  5 
   
 8   16 
To divide, multiply by the reciprocal of -5/16
 1   16 
    
 8  5 
 16  8
  8
 40 
2

5
Example 3
The formula C  ( F  32)  1.8 converts temperatures
in degrees Fahrenheit, F, to degrees Celsius, C.
What is 28.4°F in degrees Celsius?
SOLUTION
Substitute F = 28.4 in the formula C
C  (28.4  32)  1.8
C  (28.4  (32))  1.8
C  (3.6)  1.8
C  2
 ( F  32) 1.8
Homework

Page 140-142

3, 4, 7, 11, 12
Now with Rationals
1 1
4  2  
3 2
2
A harder example
 1 1 
3
3


4

2



 
 2 6

 
2
 
2