The percent is a relative unit of measure which expresses the size of some share of the general whole on comparisons with number 100. The size which is written down in a fraction format too shows the attitude of a share (numerator) to whole (denominator). It allows to transfer any number to percent, having made a proportion, it be presented in the form of natural number, a common or decimal fraction.

## Instruction

1. For transfer to percent of the number which is written down in a format of a common fraction make a proportion - level it to other common fraction in which numerator there has to be a required number of percent, and in a denominator - 100%. If to designate numerator of initial fraction as variable a, a denominator - as variable b, and required number - as x, the proportion can be written down so: a/b = x/100.

2. Express an unknown variable from the equality received on the previous step through the others his members - transform identity so that in the left part there was only required number x. In the right part there has to be an initial fraction increased a hundred times: x = 100*a/b.

3. In the decision received in a general view substitute values of variables (numerator and a denominator of initial fraction) and calculate result. If the common fraction is written down in the mixed format, before calculations increase its whole part by a denominator of fractional and add the received size to numerator. For example, to fraction 4/15 there correspond about 100*4/15≈26.67%. For the mixed and improper common fractions the result will always be more than 100%. For example, 2 7/25 is 100*(2*25+7)/25 = 100*57/25 = 228%.

4. For transfer to percent of the number which is written down in a format of decimal fraction it is possible to make a proportion, as well as in the first step. In its left part there has to be a decimal fraction transformed to a format ordinary. For such transformation in numerator put initial number from which the decimal comma is withdrawn, and in a denominator - unit with the number of zero equal to the number of figures after a comma in initial number. Further actions with a proportion are described above.

5. If the course of the decision does not need to be given, for transfer of decimal fraction to percent just transfer a comma to two categories to the right. For example, number 0.782 in percentage expression can be written down as 78.2%.

6. With natural number it is still simpler - for representation it as a percentage just add two zero on the right. For example, number 4 corresponds to 400%.