In a continuum, all converging series of locations ends in a limit that belongs to the continuum. The definition of change uses the limit of a converging series of locations. Change can be divergence, gradient, variation with time, or rotation (curl). A spherical shock front results in expansion of the continuum.
Deformation is part of the change of a continuum.
A continuum can have a real part and it can have a spatial part. In the real part, the real number calculation rules determine the arithmetic. In the spatial part, the spatial number calculation rules determine the arithmetic.
Differential calculus rules the change of a continuum.