For starters, the number, expressed as a percentage, translates into the same meaning that it has a total deductible amount. This is solved the proportion: the sum total is one hundred percent, but an unknown amount is the percentage. "Unknown amount" is the translated value, which will need to deduct from the total amount. If you write the members of the proportion below each other, respectively, it is easy to understand the principle of its decision: "criss cross". That is, the cross lying known members are multiplied and the product divided by the member, not having a pair. Example. May need to calculate a deduction of thirty-five percent of the amount of income equal to one hundred and fifty rubles. Is made proportion: 150 rubles - 100% of "x" rubles – 35 %. "X" rubles = (150 rubles*35%)/100%=52.5 ruble.
After finding the deducted value deducted from the total amount found expression. The difference is the solution of the problem. Example. Of the total income equal to one hundred fifty rubles to take thirty five percent, constituting fifty-two and a half rubles. It turns out, 150-52,5=97.5 rubles.