Hello people, how are you?

We will work in that classroom with financial mathematics

In this lesson we will see percentage definition and calculation

Come to the definition: Percentage is nothing more than a fraction whose denomindor is 100

that is the symbol that indicates percentage

So, for example, 30% is a fraction whose numerator is 30 and denominator is 100

means that 100 something to take 30.

If, for example, I say: 30% of people are women

It means that every 100 people found 30 are women Turning 30% in decimal is 0.3

Similarly 45% is 45 per 100 and in decimal results in 0.45

So generally results in x x% per 100 That is a 100 x elements considered taking them.

Come to the calculation of percentage

Let's calculate, for example, 30% of 840.

First we must discard the percentage, ie: 30% turns 30 per 100

then multiply the fraction by 840, simplifying the zeros if possible

There simply multiply 3 times 84 which is equal to 252

So 30% of 840 equals 252. ok!

Next example:

First undo the percentage cut and the zeros if possible. Do not worry about larger than 100 it exists.

Now multiply 120 times 2, which equals 240.

Now calculate the percentage of percentage That appear in various situations.

Consider 10% to 80%. How calculated?

It's easy. We have two percentages, then simply discard the first and keep the second

Undoing the first is 10 per 100 times 80% (retains)

The answer will come in percentage therefore retain the second

Conducting the accounts get 8% Then 10% to 80% and 8%

One more example with 3 percent ...

What we have to do is undo the first two and retain the final percentage

Put simply the zeros and multiplying that remains will become: 700 by 100

To simplify the two end up by the two zeros in the bottom. Finally response: 7%

Ie 25% from 70% to 40% is equal to 7%.

Watch the latest example!

We want a percentage of another rate a monetary value.

Thus we must discard all the percentages involved because the answer will come in reais.

Calculating get 20 per 100 times 110 times for 100 reais 2000

Simplify the possible zeros to get 20 times 11 times 2

resulting in 440 real!

Thank you for your attention! Watch the class 2!