OpenOffice is an opensource application suite similar to Microsoft Office but that can be downloaded for free (http://www.openoffice.org/). It allows users to create and edit spreadsheets, documents, presentations, graphics and databases. The Calc application included in OpenOffice allows you to calculate percentages in much the same way Microsoft Excel does. If, for example, you want to calculate the percentage of male students in a classroom of 300 students, Calc can accomplish this task with a simple formula.
Things You'll Need
 OpenOffice software suite

Use the "Start" button to find and launch OpenOffice Calc on your computer. A new Calc worksheet will open.

Click cell A1 to highlight it. Type "50," which is the number of boys in the class.

Click cell B1 to highlight it. Type "300," which is the total number of students in the class.

Click cell C1 of the worksheet. Type "=[A1]%[B2]" and hit the "Enter" key. The percentage of boys in the class will be displayed in cell C1.
Tips & Warnings
 When you enter the percent formula, the answer will be given in decimals. To view the answer in percentage, highlight the answer cell by clicking it, rightclick the highlighted cell and select the option "Format Cells." Select the "Number" tab in the "Format Cells" window. Check the "Percent" option in the "Category" list. The value will now be displayed in percentages, for instance 25 percent.