You will need
• pen and paper, calculator
Instruction
1
Percentage (N) is a single number (P), the latter is always equal to 100%. Thus, it turns out that our desired number has 100 equal parts, and we need to find N parts from him. We make a proportion:P=100%
?= N%is also Under question hides a number comprising we need the percentage. For the proper preparation of calculation use the rule of "crossroads". To calculate the number hidden under the question, multiply the known value of the standing crosswise and after the split on the known number of the second pair.(R* N)/100=?For clarity, we define specific values:37=100%
?=7%(37*7)/100=2,59 ie 2,59 this number represent 7% of the specified value.
2
The proportions can be of the following types:1) ?=100%
Z= N% here, Z, the number constituting a predetermined percentage from an unknown whole number.
The formula is: (Z*100)/ N=?2) R=100%
Z= ?% calculation formula: (Z*100)/P=?
3
But how to calculate percentage on a calculator when the numbers are large, and in their mind to divide and multiply there is no time or opportunity? Or to perform actions according to the above formulas, or to simplify a task and to carry out a program of action. They are standard on all models of calculator.Enter the number, percentage from which you want to find.Press multiply (X), the value of the desired percentageand then "percent" (%) – the latter performs the action of dividing by 100.