Scientific Notation on the TI30X-IIS

Now we're going to look at an example
problem using our calculator.

This is the TI thirty X two S,
and this is the model I recommend.

Other calculators will do the exact same functions,
but things happen in a little bit different order.

And where the buttons are and what
they call them are a little bit different.

So if you're not sure how to use your
calculator, play around with it.

And if you still need help, then please
feel free to come see me.

We're going to solve this problem, and we're
using numbers that are in scientific notation.

And I want to show you how to enter
this correctly into your calculator.

So my problem is six point one times ten to the fifth,
divided by one point two times ten to the minus third.

So I have two issues I have to worry about:
one, how do I enter this number (the 6.1 x 10^5)

in scientific notation into my calculator,
and how do I enter the denominator correctly

so that the right calculation is done.
So, we're going to turn our calculator on.

And I'm going to type 6.1, and then
I have the times 10 to the fifth.

The way we do this on the
calculator is we use this EE function.

So if I look here at this button that has
x to the -1, above it in purple it says EE

and that means scientific
notation--the exponent.

So I'm going to hit 2nd because I wanted
to use the purple function there.

I press EE, so it shows an E on my screen.
And then I put a 5 in.

Now note, I did not put a multiplication sign in,
I did not type 10, I just put 6.1 E to the fifth.

And that means exactly the same as this:
6.1 times 10 to the fifth.

Now I'm going to divide, then I'm
going to put in my denominator: 1.2.

Again, I'm going to use my EE function,
so I do 2nd, EE.

And this time my exponent is to the negative
three, so I use my minus sign here,

this is the negative sign--excuse me, the negative
sign, not the subtraction sign--minus three.

And when I hit equals, that will show me my answer.
And it's showing it here in scientific notation.

So, I have 5.1--because I'm going to round it to
one decimal place--5.1 times ten to the eighth.

So, we're going to write that down.

Now, sometimes your calculator won't
be showing it in scientific notation,

or you want to get something
out of scientific notation.

And what you do is you
use the 2nd button again.

And here where it has DRG which stands for degree,
above it you see SCI/ENG, so "scientific/engineering."

So, I hit 2nd and scientific/engineering, and I want
to make sure SCI--that will put it in scientific mode.

If I want to just see the number NOT in scientific
notation, I choose FLO for "Flo" [floating decimal]

and that will show me the
number NOT in scientific notation.

So here you don't see the times ten to the eighth,
you see the whole number written out.

And I can go back to scientific notation,
and now again it shows it in scientific notation.

So, that's the correct way to do the problem.
What I want to show you is how you DON'T

want to do this, because I want you to see
that there is a difference in the answer.

So, here we've used the EE function,
our scientific notation, to show these values.

Let's look at what happens if instead of using
the EE button, I use "times ten to the fifth."

Now for the numerator it
doesn't make a big deal.

However, we're going to run into a
problem with our denominator.

I'm going to hit divide, one point two,
times ten to the minus third.

Now, when I hit the equals sign,
I get my answer, it's in scientific notation.

But, note it's five point one times ten to the second,
a very different answer than what I saw before.

And the reason for that is because what
really happened is the calculator took

6.1 x 10^5 divided by 1.2
and multiplied by 10^-3.

And that's not what we wanted to happen,

so you need to make sure you use scientific
notation so that you get the correct answer.