Color print 1280 X 960 GIF Grayscale print Tutorial back Values table Symbol key Tutorial next At each point in the above space, a quantity is being represented with both the numerical value portion and the units of measure portion visible, both are expressed as a power of ten, calculation of both is visibly obvious as being performed by the addition of exponents, and it is easier to accomplish the purpose of any map: to look at the problem is to solve it.