How to determine the percentage of the amount

The tasks for the interest you have to face not only the students. As a rule, in school assignments, we either need to find a numerical expression of a certain amount percent, or what percentage of something a number. To successfully overcome such challenges, it is first necessary to understand that a percent is a hundredth part of something whole. This whole can be, for example, the sum of several numbers.

You will need

• - the numbers that make up the amount;
• - any computing device;
• - a sheet of paper;
• - a pencil or pen.

Instruction

1. For example, the need to find out what the percentage of the total is each of the summands. Indicate the number that need to be folded in any letters. For example, let it be integers a, b and c, and the sum of them is equal to d. Then the sum d, which in scientific literature is usually denoted as σ, is equal to a+b+c.
2. Find one percent of the amount. This requires a number d divided by 100. Now you need to find what percentage of the total is each of the summands. That is, you need to consistently know how many times the numbers a, b and c "fit" in a numerical value of 1%. To do this, divide by this value each of the components.
3. Such tasks are convenient to solve by using proportions. Take the number of d for 100%, and the desired summand for x will the ratio d=100% and=x. Remember how to write the equation with such terms. The unknown variable is found by multiplying the number and 100% and dividing the resulting works on the amount of d That can be expressed by the equation x=a*100/d.
4. In exactly the same way we can solve the problem, where a known amount and what percentage of it is each of the summands. In this case, as unknown indicate the number and proportion will look like the following: d=100%, x=35%. Write down the equation as a fraction, the numerator of which is the product of the number d and 35%, and the denominator is 100%, i.e. in this case x=d*35/100.