  We propose a new macroscopic model derived from the classical nonlinear
Boltzmann equation. A set of partial differential equations is obtained easily.
The unknowns depend on the time and space coordinates, and are related to the
distribution function, which is the unknown of the Boltzmann equation. This new
model guarantees the conservation of the mass, momentum and energy. We prove
that the set of equations coincides with the system obtained applying the
discontinuous Galerkin method to the Boltzmann equation (see A. Majorana,
Kinetic and Related models, 4 (2011), 139--151).
