8:47. ; The base unit of time is the only one that is not metric. meters. However, we often deal with larger or smaller lengths or distances for which multiples or fractions of the fundamental unit are more useful. A similar statement holds for derived units: for example, kg/m3, g/dm3, g/cm3, Pg / km3, etc. A change in position with respect to a reference point is * 1 point A. acceleration**** B. velocity C. speed D. motion 3. SI has seven basic units, from which others are derived: the second, the meter, the kilogram, the ampere, the kelvin, the mole, and the candela. A few special points about some of these units are worth noting: The base unit of mass is unique in that a decimal prefix (Table \(\PageIndex{2}\)) is built into it; i.e., the base SI unit is not the gram.