What is a Variable in Science Terms?

A variable in science can represents units of data in the analysis of a specified research or representations of symbols in mathematical equations. For example, a variable in social science might be income, prices, ages, population). A variable in science and math might be a letter(a,b,c), numbers, points(point a, point b) or even a unit of measurement in quantity(3 litres, 4 lbs) and so on.