The words per cent and percentage are closely related—does it matter how they are used in a sentence? The rule for using per cent and the percentage is straightforward. The word per cent accompanies a specific number, whereas the more general word percentage is used without a number. The term ‘per cent’ means one out of a hundred. In mathematics, percentages are used to describe parts of a whole – the whole is made up of a hundred equal parts. The percentage is used commonly to show that the number is a percentage, less commonly the abbreviation ‘pct’ may be used.