3.4pemdas(teacher)
TRANSCRIPT
The Order of Operations
Section 3.4
Today’s Objective
• Recall PEMDAS
• Perform the proper order of Integer Operations
The Order of Operations
The Order of Operations• Number sentences and equations MUST be
solved in an exact order.– Parentheses– Exponents– Multiplication & Division –in order from left to
right– Sometimes you will divide before you multiply!
– Addition & Subtraction –in order from left to right-Sometimes you will subtract before you add!
The Order of Operations(PARENTHESES
)We always do parentheses first.
[Brackets are square parentheses.]
If there are no parentheses, skip this step.
The Order of Operations
EXPONENTS2
Exponents are also known as “powers” (e.g. two to the third power)
23= 2 x 2 x 2 = 4 x 2 = 8
We now interrupt this show for a mini-lesson on MANNERS!
If you were to walk down the street and see two people you know, you would greet the person you come to first… and not ignore them to talk to the second person first … I HOPE! You can talk to the second person in a minute.
Ready????
Good Manners
Mr. Division
Ms. Multiplication
Hello Ms. Multiplication! How are you
today?
Hello Mr. Division! How
are you today?
Doing great,
thanks! Gotta fly!
Kinda tired today, but thanks for
asking!
In this case, we talked with multiplication first, then
division because that was the order in which we met them. We did what was
polite! Hooray!
Good MannersMs.
Multiplication
Mr. Division
Hello Mr. Division! How
are you today?
Hello Ms. Multiplication! How are you
today?
Not bad at all! Walking in my
sleep is a great way to get exercise!
Fantastic! There is no
traffic up here!
In this case, we talked with division first, then
multiplication because that was the order in which we met them. We did what
was polite! Hooray!
Bad MannersMs.
Multiplication
Mr. Division
Ms. Multiplication! I need to see you!
Hold on a minute!
Why didn’t you talk to Division
first?
But I thought I was supposed to
see you first!
Nope! You blew it, Buddy! How rude! What
am I? Chopped liver? I was here
first!
But I thought…Oh, Boy! I guess
I was wrong!
Oops! You blew it! Never ignore the first person to get to
the second! It is rude and wrong!
Now back to our regularly scheduled program!
You need to practice the manners lesson for the next two steps…
With multiplication and division, you need to “talk to”whichever comes first.
– Sometimes you will multiply first then divide.– Sometimes you might divide first then multiply. – Sometimes you may have to multiply, divide, then
multiply again. – Sometimes you may only have one of these
operations.The same rule applies for addition and subtraction!
The Order of Operations
Multiplication = Division
Multiplication and Division are equals! Do them in order left to right. Sometimes you might have to do division first. Think of our mini-lesson on manners!
The Order of Operations
Addition = Subtraction
Addition and Subtraction are equals! Do them in order left to right. Sometimes you might have to do subtraction first. Think of our mini-lesson on manners!
Good Manners
Mr. Subtraction
Mr. Addition
Hello Mr. Addition!
How are you today?
Hello Mr. Subtraction! How are you
today?
In a hurry! Gotta run!
A bit under the weather…
It will pass!
Good MannersMr. Addition
Mr. Subtraction
Hello Mr. Subtraction! How are you
today?
Hello Mr. Addition!
How are you today?
Not too bad! I think this rain is
helping me grow!
Great! Getting my exercise!
Bad MannersMr. Addition
Mr. Subtraction
Mr. Addition! Can I talk to you
for a minute!
Why didn’t you talk to Subtraction
first?
But I thought I was supposed to
see you first!
What am I? Chopped liver? I was here first! Rude people!
But I thought…Oh, Boy! I guess
I was wrong!
Nope! Don’t be rude! Talk to the dude who comes
first!
Example #1Always show all of your steps!
(2 + 3) x 9x 945
(2 + 3) x 9 = 45
5
Example #2Always show all of your steps!
16 ÷ 4 x 24 x
2816 ÷ 4 x 2 = 8
Example #3Always show all of your steps!
9 x (3 – 1) ÷ 62 ÷ 69 x
÷ 6183
9 x (3 – 1) ÷ 6 = 3
Example #4Always show all of your steps!
6 - 3 x 2 + 46 - 6 + 4
+ 404
6 - 3 x 2 + 4 = 4
Example #5Always show all of your steps!
(14 - 10)2 ÷ 8 = 2
(14 - 10)2 ÷ 8÷ 8(4)24 x
4 16 ÷ 82
Let’s Practice…
Practice #1
(4 + 6) ÷ 5 – 2
(10) ÷ 5 – 22 – 2
0Answer:
(4 + 6) ÷ 5 – 2
Practice #2
7 x 9 ÷ 3 – (8 – 5)
7 x 9 ÷ 3 – (3)63 ÷ 3 – (3)
18Answer: 21 – (3)
7 x 9 ÷ 3 – (8 – 5)
Practice #3
36 ÷ 6 + 3 x 5 – 2 x 336 ÷ 6 + 3 x 5 – 2 x 3
6 + 3 x 5 – 2 x 3
15Answer:
6 + 15 – 2 x 36 + 15 – 6
21 – 6
Practice #4
Answer: -10
Practice #5
Answer: 0
EXIT TICKET
-3 x (3 x 5 - 3 x 8)