Quantitative variable: a number must be used to measure a quantitative variable. Also, addittion and subtraction between two different measures has meaning. Qualitative variable: it is an attribute or characteristic of an individual. Sometimes a number is used as a qualitative variable, but, in this case, addittion and subtraction between two numbers has no meaning.
Work Step by Step
Examples: - quantitative variable: the height of individuals, the mass of a banana, the volume of water in a cup, etc. - qualitative variables: hair color, nationality, ID number, etc. Note that the ID number is a number, but we do not add or subtract two different ID number because it has no meaning.