hey everyone it's kayleigh this lesson is an introduction to the order of operations the
order of operations is super important as we get further along in our math education ready let's go
let's imagine that the final calculation for sending a rocket into space is eight
plus two times three and two different scientists are going to do this calculation
so the first one has the same problem eight plus two times three and they decide to do it like this
eight plus two that will give them 10 times three so they did the addition first and then they're
multiplying by three and they get an answer of 30. okay now the second scientist also has this same
problem 8 plus 2 times 3 and they decide to do the multiplication first so they do 2 times 3 first
and that gives them 6 and they still have to add this 8 here so they have 8 plus 6 and their answer
is 14. now these are two very different numbers right and in math we really don't like getting
two different answers so how do we know which one of these answers is correct well we have
this thing called order of operations and every mathematician and scientist agrees to follow the
order of operations this way when we need to send a rocket into space we make sure we have
all the right calculations the order of operations goes parentheses so you do what's inside the
parentheses first then exponents probably you don't know what exponents are yet and that's
okay we aren't going to need them in this lesson and then we have multiplication and division
and they're on the same level or the same priority and lastly we have addition and subtraction
and those are also on the same level or they're the same priority as each other
so looking at the order of operation which scientist has the correct answer
yeah that's right this one over here in the pink because they did multiplication first and then
addition as if we go down our list we see multiplication and division
comes before addition and subtraction let's do a few examples together so here we have a
problem to solve and we're going to use the order of operations now the first thing i'm
going to do is write this problem here in my own handwriting so i have 14 divided by 12 minus 5.
now let's take a look at our order of operations what operation do we do first first things we have
parentheses do i have parentheses in my problem i sure do right here 12 minus 5 so we do that
first 12 minus 5 gives us 7 and then to bring the rest of the problem down so i have 14 divided by 7
and now division is my only operation so i can just go ahead and do it 14 divided by 7 is 2
and there we have it that's the problem see it's not so bad using order of operations right
okay let's take a look at this one i'm going to start by writing my problem down i have 4 plus 9
divided by 3. now taking a look at my list over here do i have any parentheses in my problem
no do i have any exponents in my problem no of course not now multiplication or division do i
have that in my problem i sure do right here so i'm going to go ahead and do that first
9 divided by 3 that gives me 3 and i bring the rest of the problem down i still have
4 plus 3 so i've done my multiplication and division check and now addition and subtraction
i have that 4 plus 3 get gives me 7 and there we go that's the answer now let's do one more
advanced example to finish off the lesson oh so see this is a long one here first thing i'm going
to write it in my own handwriting so i have 7 plus 3 times 4 divided by 2. now if i take a look over
here at my list my order of operations i'm going to see do i have any parentheses in my problem
i do right here so that's what i do first 7 plus 3 that gives me 10 i bring the rest of the problem
down so i have times 4 divided by 2. perfect so we did that do we have exponents no exponents
we have multiplication and division in our problem yes we have multiplication here and
division but these are on the same level right they're the same priority so which one do i do
first when we have both operations from the same level we just work from left to right so we start
with whatever operation comes first and we then go to the next one so working left to right i have
10 times 4 this comes first and then my division will come second so 10 times 4 that gives me 40
i bring the rest of the problem down divided by 2 now i can do my division and i get 20 and that's
the answer nice work good job you're ready to do some practice problems on your own make sure
you look back at the order of operations list to help you out have fun and remember to always be
clever