Numerical solutions of the Dirac equation applied to low-energy electron scattering are presented. The calculated complex scattering amplitudes are used to discuss single, double, and triple scattering. Although knowledge of all three experiments leads theoretically to the explicit scattering amplitudes, the calculations show that the amplitudes can be determined, with a reasonable uncertainty only from high-precision experimental data. This is a consequence of the fact that | g | is normally very small compared to | f |. However, for very selective combinations of the experimental parameters, a very strong influence of the spin on the scattering process is predicted. How this result can be utilized in studies of electron exchange scattering and in investigations of spin-flip processes is discussed. The important quantities for triple scattering from tungsten were calculated for different scattering potentials in an energy range 50 eV - 200 keV. The dependency of the observables on the incident electron energy and scattering potential is shown.