### Video Transcript

Determine, to the nearest cent,
the total price of an inflatable dolphin that costs five dollars and nine if the
sales tax is 4.25 percent.

So, what we do first is rewrite
the question so we can see exactly what we’re asked to do. And that is increase five
dollars and nine by 4.25 percent. So, if we want to work out the
total price of our inflatable dolphin, what we want to do is add on 4.25
percent. And we can do this using the
multiplier method. And the multiplier for an
increase of 4.25 percent is gonna be 1.0425. But how do we get this?

Well, there’re a couple ways of
thinking about it. The first is if we think about
the whole amount, that’s 100 percent. And if we want to increase it
by 4.25 percent, we’re gonna have 100 percent plus 4.25 percent, which is 104.25
percent. And to have a multiplier, what
we want to do is convert it into a decimal. So, as percent means out of
100, or by the 100, we can divide this by 100, which is gonna give us
1.0425. So, that’s one way of finding
out what the multiplier would be.

The other way of considering
the multiplier is to think that one is gonna be the whole of something. And then, we’re gonna add 4.25
percent to it, which is gonna be one add 4.25 over 100. And that’s because 4.25 over
100 will give us it as a decimal, which would give us one plus 0.425, which,
once again, would give us our multiplier of 1.0425. Okay, great, so now we’ve got
our multiplier, we can calculate the value of this question.

So, what we do to calculate the
total price after the sales tax is multiply 5.09 by 1.0425, which is gonna be
equal to 5.306325 dollars. Well, have we finished
there? Well, not quite because the
question asked us to leave it to the nearest cent. Well, if we round to the
nearest cent, we’re gonna look at the second decimal place. So, then, we can see the digit
that’s to the right of this, which is a six. Because it’s five or above, we
round the zero to a one. So, we get five dollars and 31
cents.