Welcome to Excel and business math video number 17.
Hey, in this video, we've got to talk about fraction business
math word problems.
We'll see how to do two examples by hand and in Excel,
and we'll get to see how to make sure,
when we're given something like 3/10 of a penny,
we can either write it in the unit cents or in dollars.
Let's go look at our first example.
I'm going to click on the sheet Word one.
Here's our first problem.
An experiment done with 600 smokers
was conducted to see if a particular stop smoking chewing
gum could help people quit.
After four months, 2/3 of the smokers were still smoking.
Rounding to the nearest whole number,
how many smokers in the experiment stopped smoking?
Now right off the bat even before I list the facts,
I'm going to list the goal.
How many smokers in the experiment stopped smoking?
Determine number of smokers in the experiment
who quit smoking.
Now let's list our facts.
Now it looks like we have 600 smokers.
And since we're given a fraction here--
that means a certain part of the original--
that 600 is the whole or the total.
And then they'll be two parts of that original total--
the number who are still smoking and the number who
stop smoking.
So I'm going to list facts.
Smokers in the experiment-- that's the whole or the total.
That's 600.
Fraction of smokers still smoking--
that's going to be part number one.
And I want to enter that in a very particular way.
We talked about this before.
If we have certain fractions with many repeating decimals,
it's much better to enter a formula like this
because 2/3 is as exact as we can get.
It's more accurate than if we type point 0.66.
So we will Control Enter.
And let's format this, and I'm going
to use the built in fractional number
formatting since we have just a single digit in the top
and bottom.
Now the rest of this-- it says rounding
to the nearest whole number.
I'm actually going to list that here as one of our facts.
Round answer to the next whole number
and remind ourselves that when we're rounding to the one's
position we use a zero.
Now we can solve.
Now there's actually a few different ways
that we can solve this.
One way is, since we're given this part of smokers
who didn't stop--
and notice up hear, it reads 2/3 of the smokers.
Well, the smokers are the 600.
2/3, that's the part.
And of, that means multiplying.
So down here, I can calculate the actual number
of smokers who did not stop smoking and tap.
Now we can do a formula equals, up
arrow to get the actual total number of smokers, times--
that's the word of--
up arrow to get our fraction of smokers who are still smoking,
Control Enter, and there we get our part of the total.
Now the actual cell references pull that fractional number
formatting.
So with the cell selected, I'm going
to go up and apply general and I'm
going to add some green there.
Now that's not the part we're after.
We're after the other part.
So now we can simply take, hey, all of them or the whole,
subtracted the ones still smoking,
and we'll get number of smokers who did stop smoking.
So are you ready?
It equals up arrow to get the total minus those still smoking
Control Enter.
There's our answer--
200 actually use the gum and quit smoking
at least after four months.
I'm going to click that green.
Now I want to check the answer.
I can calculate smokers in experiment.
These are the two parts.
I want to add them up--
alt equals, highlight.
I'd better get the same original 600.
I could also do this a second way.
I could actually calculate the fraction
of smokers who stop smoking.
Well, if 2/3 is the fraction of people
who are smoking, if I take 100% or 1 and subtract 2/3,
I'd better get that fraction.
So it equals 1 minus this 2/3.
And that number for many will be polled, Control Center,
and there it is-- one third.
And then I could check number of smokers who did stop smoking
equals one third times the original 600 Control Enter.
It's got that number formatting.
So I'm apply general.
Now we can write our answer, and I actually
am going to use that for months up here just
to qualify the written statement.
So there it is.
After four months, 200 of the total 600 smokers
stopped smoking.
Let's go to our next sheet, word two.
All right this problem reads, the utility company
says that the cost of operating a hair dryer
is 3/10 of a cent minute.
Notice that's the unit--
so cent, so we're going to have to take 3/10 of a cent
and, remember, per means division.
Find the cost of operating the hairdryer for 30 minutes.
So really the hard part is going to be
making sure we get the correct number for cost per minute.
And then we can multiply it by 30 minutes.
We'll list the goal first--
find the total cost of running the hairdryer for 30 minutes.
Now I'm going to pull this drawing,
this hand-drawing I did over here.
Because the trick is is it's given as 3/10 of a penny.
So really, it's as if we took 3/10 as a fraction
and multiplied it by a penny.
Well, how do we get 3/10 to a decimal?
Well, we do our division.
How many tens are in three?
Well, there's not a whole 10.
So we put a decimal point in the decimal up here and put in a 0.
Then we ask how many tens are in 30, 3, making
sure to list that zero.
So 0.3.
It's still as a cent, though.
When we take that and multiply it by a whole penny,
we're given in the units of pennies 0.3.
But we could also say, because one penny equals 0.01
with the unit dollar, we can make
the calculations this way--
3/10-- that's the fraction-- times 0.1 dollars.
Notice that's the hundredth position.
So we could list it with the unit still there--
3/10 times 1 over 100.
We'll multiply the numerator, multiply the denominators,
and we end up with, in dollars, 3 divided by 1,000.
Of course, now we have a huge denominator.
How many thousands are in three?
Well, we have to put our decimal.
Repeat the zeros.
And up here, decimal 0.0, it's not until we list three zeros--
3,000-- that we can get 1,000 to go into it.
How many thousands are in 3,000?
3.
We put it right there.
So that's the amount of dollars right there with the unit.
So notice that 3/10 of a cent can
be written as still with a unit cent, 0.3 cents, or changing
the units, $0.03.
So listing our facts--
cost of operating the hairdryer per minute.
I'm actually going to try and write this with a cent unit.
3 divided by 10.
And guess what?
There is no number formatting for cent.
So over to insert, over to symbols.
Symbol, and I'm going to try and find a cent.
Now the only place that I found cent was font equals Ariel,
and I had to scroll down, and there it is.
I found cent.
So when I find it, I click Insert.
Now I already had it listed as my recent,
but when I click Close, there it is.
Now this is not a number.
This is going to be text.
We'll have to convert it to a number down in our calculation
area.
One penny listed in units of dollar--
well, I know how to do that.
I'm going to type 0.01, and then come up to home
and apply currency.
Now I'm going to list the fraction.
I listed a fraction of a cent equals 3 divided by 10.
That's the fraction they gave us.
Now it comes up as 0.3.
Excel was polite enough to convert it to a decimal for us.
So now we create a label that says
3/10 of a cent in dollar units.
So it equals 3/10 times our penny.
So that's what it means.
We're going to charge zero.
That would be great.
You could run your hair dryer and never get charged anything.
That's number formatting.
Currency by default shows to decimals,
but this is a situation where we're
going to increase the decimals because the actual charge is
less than a single penny.
And there it is.
Now we simply calculate total costs
for running hair dryer for 30 minutes
equals there's the cost per minute times--
and I'm arrow up to get 30 minutes.
And it will take that proper unit right there
and Control Enter.
That's it?
Just nine pennies?
I can blow dry my hair for 30 minutes,
and it will only cost me nine pennies.
Now we can check our answer.
Let's look at this formula right here.
Notice we took 30 minutes times 0.003.
So I'm going to do the reverse and do division.
I'm going to take whatever the answer is, nine pennies,
and divide it by 0.003 and I better get 30.
So over here, I'll try to calculate
total minutes equals--
there's the answer-- divided by 3/10 of a penny Control Enter--
there's our check.
I'm going to add some green.
I'm also going to add some green over here also.
Now we can check this a different way.
We actually could have taken a whole different approach.
Up hear, I could have written fraction of a penny
and then done our 3 divided by 10 fraction,
apply our fraction number formatting.
And then down here I can jump to the chase.
Instead of converting it to dollars,
I could have just said answer in pennies equals--
and look at that.
I got tricked by a number formatting.
Man, I'm lucky I caught that.
But watch this.
I'm going to take the 30 minutes times,
and this formula will not be tricked by number formatting.
It'll see the underlying.
Control Enter, I'm definitely going
to come up and apply General.
Up here, Control 1, and I want fraction.
And I'm going to look for--
there's a 10th.
Click OK.
And now the answer is given in pennies.
Check.
Now we can write our answer in words.
The total cost of running a hairdryer for 30 minutes
is nine pennies either unit--
Enter.
That was a little fun with business math word problems
and fractions.
There's one, two, three homework problems for you to practice.
And of course, if you like that video, click that thumbs up,
leave a comment, and sub because there's always
lots more videos to come from from Excel
is fun, including next video 18.
That'll be the start of our percentages topic.
We'll see you next video.