  We have calculated the strength distributions of the giant monopole resonance
in the even-A tin isotopes (A = 112-124) which were recently measured in
inelastic $\alpha$-scattering. The calculations were performed within two
microscopic models: the quasiparticle random phase approximation (QRPA) and the
quasiparticle time blocking approximation which is an extension of the QRPA
including quasiparticle-phonon coupling. We used a self-consistent
calculational scheme based on the HF+BCS approximation. The single-particle
continuum was exactly included on the RPA level. The self-consistent mean field
and the effective interaction were derived from the Skyrme energy functional.
In the calculations, two Skyrme force parametrizations were used. The T5
parametrization with comparatively low value of the incompressibility of
infinite nuclear matter ($K_{\infty}$ = 202 MeV) gives theoretical results in
good agreement with the experimental data including the resonance widths.
