Another kind of fraction is the

*percentage*(Latin per centum*meaning*"per hundred", represented by the symbol %), in which the implied denominator is always 100. Thus, 51%*means*51/100.*Percentages*greater than 100 or less than zero are treated in the same way, e.g. 311% equals 311/100, and −27% equals −27/100. The related concept of permille or parts per thousand (ppt) has an implied denominator of 1000, while the more general parts-per notation, as in 75 parts per million (ppm),*means*that the proportion is 75/1,000,000. Whether common fractions or decimal fractions are used is often a matter of taste and context.