WEBPhysical Science: Tables & Formulas. SI Base Units. SI Derived Units. Prefixes used to designate multiples of a base unit. In general, when converting from base units (m, l, g, etc) or derived units (m2,m3, m/s, Hz, N, J, V, etc) to a multiple greater (kilo, mega, giga, or tera) than the base or derived unit- then divide by the factor.