Calculation of percentage of the number - one of the fundamental fact that all are in school in math class.But this does not mean that all master it easily.In fact, the theme is simple, the main thing - to know the proven methods of calculation on the part of the whole and the interest of the whole.

1% - a hundredth part of the whole, so that, knowing this value, you can easily calculate the value and the unit.For example, 15% of 60 can be calculated as follows: take 60 for 100 percent.Then 1% - is 60/100 - 0.6.15%, thus, amount to - 0.6 * 15 = 9. This is the first way to calculate the percentage of the number.

second way - to make proportion.15 refers to the 100 as the X refers to the 60, that is 15/100 = x / 60.Solve the proportion made up in two ways:

- transform it into an expression x = 15 * 60/100.Again, it turns out: x = 9.
- make another transformation in 2 steps: 100x = 15 * 60, that is, in the proportions of multiply crosswise.From this we obtain the following expression: = 100 x 900. Therefore, x = 9.

If you want to figure out what percentage of the number of another number, the formula is also very simple.Take for example the number of 70 and 13 May 70 - it is 100%, and 13 - x.Then x = 13/70/100.Solve this proportion may be already familiar ways.

the 70 * 13 = 100;70s = 1300;When rounded to two decimal places, we find that x = 18.57%.

If you know a certain percentage of the number and need to find the number, then this problem can be solved completely.

For example, 16% - 32. What is an integer?Again compose proportion: 16% refers to 100% as well as 32 to x.16/100 = 32 / x;16x = 3200;x = 3200/16 = 200.

If the condition of the problem is such that the number of A is a certain percentage of the number of B, which should be calculated, then applied another very simple formula.A / B * 100% - this will be the answer.For example, you need to figure out what percentage of the number 87 is the number 329.

calculate the result from the formula, we get 87/329 * 100% = 26.44%.If the formula is forgotten at the right moment, once again come to the aid of the ratio: 87 329 relates to how x refers to 100%, i.e. x = 87/329/100.Transforming this proportion, we get 329h = 87 * 100;329h = 8700;x = 8700/329 = 26.44%.

Well, the simplest proportions in virtually all always hearing in my head: one-fifth - is 20%, one-tenth - 10%, half and a quarter - 50% and 25%, respectively.For some, it is more convenient and clearer thoughts often, and someone is easier to operate percent.The big difference between one second and 50% do not.

with a calculator and all will be easy, because there is even a special button that allows you to calculate the percentages.

course, all of these problems - a consolidation theory.However, to calculate the percentage of the number may need in life.On sales to find out whether a 30% discount to grasp at a thing, or it is a paltry sum.You can find out what was the price before discounts and recheck sellers - often because they are inattentive and buyers indicate the price tag is very attractive figure.

Calculate the percentage of the number may be required in the calculation of taxes, of course, for those who track such things.And, of course, with the calculation of interest are constantly faced accountants, economists, stockbrokers and analysts.In fact, even a housewife constantly have to deal with interest, without even noticing.

word, the theme is simple, though it looks very difficult.However, when it comes understanding tasks related to the percent of the number of parts and the whole, seem seeds.You just have to fill out and a little loaf.