today's lesson how to do scientific

notation on your calculator this is one

of the most frustrating things in the

world for me to teach because frankly no

one listens to me and people get things

wrong all the time because they don't

know how to use scientific notation on

their calculator they do it their own

way and they get it wrong so how do you

put a number in introducing the e button

locate that button on your calculator oh

what's that you don't have a calculator

well I told you to bring a calculator

every day not my problem you should

really have one if you don't have one go

buy one you should have your own

calculator every day because different

calculators are going to look different

you're not you're going to learn how to

use one calculator then you're going to

steal some of the other calculating you

want how to know how to use it it's

really important that you learn how to

do this on your calculator and always

have that same calculator because I did

not wish to teach you in the middle of a

test how to use your calculator I'm

doing that now I'd rather not do this

again

so the e button the e button is going to

look like one of these three things it's

silly they're going to look like a

double e as in this old TI model the e e

button the scientific notation button is

right here for that one for Casio what

you generally shows up on the bottom and

it looks like an exp right here or we

have a lot of you're familiar with this

one this is the one that the math

department uses it's this button right

here this I can't get it to focus but

right here this time is 10 to the in

button right there so please locate that

on your calculator that's what it is

that's where to find it if you can't

find it I'm going to you'll probably

pause the video here make sure everyone

in the room has found that button on

their calculator those are all different

labels but they all do exactly the same

thing it takes the number that you just

didn't put it and then put it and then

it puts in a times 10 whether it shows

it or not it puts it in

and and then it waits for your exponent

it waits for your exponent so if I have

for example three point zero seven times

ten to the fourth and I want to put that

into my calculator I'm going to hit

three point zero seven I am NOT going to

hit x I'm not I'm just going to hit my e

button put it in scientific notation the

three point oh seven and now I'm saying

hey I want this in scientific notation

calculator so I just hit the scientific

notation button and different

calculators show it differently this

calculator puts a capital letter E there

other calculators if I were to use the

math calculator I hit three point zero

seven and whenever I hit this times ten

to the button it comes up times ten to

the so it's pretty obvious that they put

that ten in there and it's waiting for

that exponent and on the old key is the

EES over here it's going to look like

three point zero seven and then my EE

button here and on this particular

calculator shows doesn't show the ten at

all it just shows the exponent you can

tell that I'm waiting for the exponent

so if I had a four now it shows up as

the exponent but a four here comes after

the e if I had a four here comes up as

an exponent now if you have this

particular calculator a lot of times

it's confusing how to get out of

exponent mode on this one you just hit

the right button and that gets you back

down into regular mode so different

calculators different ways of getting

there and they'll all look different but

those are all the same numbers those are

all thirty thousand seven hundred

written in scientific notation so make

sure that you know what that looks like

on your calculator similarly when you

get a number out when you do a

calculation and it shows the answer it's

going to show it in this format if you

have this calculator it's not going to

say x ten you need to know that's times

10 to the fourth when it puts that

little exponent up there

and for this calculator if you ever see

a capital e that means it's in

scientific notation and so if I hit

equals on all these it will give me a

decimal answer as long as it fits on the

screen these will just this will spit

out decimal answers when you hit equal

so so now let's see there are other ways

people can put these in but they involve

knowing what you are doing and I don't

trust that that's the best way to teach

you how to do it so let's say that I

want to divide two numbers I want to

divide 3.07 times 10 to the fourth

divided by six point two times 10 to the

negative third and I want to know what

that number is well for the Casio model

and the TI model these are actually both

very easy things to do you can just put

the first number in 3.07 times 10 to the

fourth 3.07 times 10 to the fourth by

the way some models of the TI you have

to actually hit the second function to

get to the e e to get to the scientific

notation I find that annoying but anyhow

you have that now you hit divided by six

point two times 10 to the negative third

do that over here divided by six point

two times 10 to the negative third and I

hit equal on both of those and I get the

same number that's good that's good

got the same number notice that I didn't

put in parenthesis probably should have

but on these calculators when you're in

scientific notation it knows that you're

in scientific notation and it groups

those together like you're thinking

however with the math department

calculator this is not the case that are

very particular about orders of

operation on here so if we put that same

number in 3.0 seven times 10 to the

fourth divided by six point two times 10

to the negative third this is not going

to give you the

same answer notice that our number back

here was in the 1-1 dude like 4.9

million yeah it's in almost 5 million

whereas this number is almost 5 so we

got a difference of about a factor of a

million and this calculator did the

right thing in this calculated the right

thing they're just kind of programmed to

handle these numbers in different ways

this one uses the strict mathematical

interpretation that we are just because

you didn't put any parentheses in there

lets the difference is that this

automatically groups scientific notation

numbers that kind of puts the

parentheses in here when you use

scientific notation and this one doesn't

if you do the same calculation without

parentheses notice that we're taking

three point zero seven we're then

multiplying it by 10 to the fourth we're

then dividing it by six point two and

then we're taking that answer and taking

it times 10 to the negative third and

that's a different answer than if we

divide by that whole group you're going

to get a significantly different answer

so if you have this calculator you

better make sure to always use

parentheses I know your math teachers

say to always use your parentheses and

that's not bad advice it's just that

these other calculators are smart enough

with grouping scientific notation

numbers that you don't have to although

it never hurts to put them in

parentheses so go ahead and do a few

divided by now this matters in dividing

it's when you're dividing and you're

dividing scientific notation numbers you

either got to have kind of calculator

that can handle it easily or you've got

to make sure to always put your

parentheses in and that's something that

is going to come up a lot so you better

learn how to do it