  A procedure based on the semiclassical approximation for high energy levels
is developed to yield solutions to the classical equation of charge motion and
to the Bargmann-Michel-Telegdi spin equation. To this end, exact solutions to
the Klein-Gordon and the Dirac-Pauli equations are used. The essence of the
procedure under review is that the quantum state of a charged particle in a
homogeneous magnetic field is represented as a superposition of states
corresponding to the neighboring energy levels. As a consequence, the behavior
of the expectation values of the momentum and spin operators with respect to
the resulting nonstationary wave function (packet) strictly obey the classical
equations of charge motion and spin precession.
