  We study the decay phase of solar flares in several spectral bands using a
method based on that successfully applied to white light flares observed on an
M4 dwarf. We selected and processed 102 events detected in the Sun-as-a-star
flux obtained with SDO/AIA images in the 1600~{\AA} and 304~{\AA} channels and
54 events detected in the 1700~{\AA} channel. The main criterion for the
selection of time profiles was a slow, continuous flux decay without
significant new bursts. The obtained averaged time profiles were fitted with
analytical templates, using different time intervals, that consisted of a
combination of two independent exponents or a broken power law. The average
flare profile observed in the 1700~{\AA} channel decayed more slowly than the
average flare profile observed on the M4 dwarf. As the 1700~{\AA} emission is
associated with a similar temperature to that usually ascribed to M dwarf
flares, this implies that the M dwarf flare emission comes from a more dense
layer than solar flare emission in the 1700~{\AA} band. The cooling processes
in solar flares were best described by the two exponents model, fitted over the
intervals t1=[0, 0.5]$t_{1/2}$ and t2=[3, 10]$t_{1/2}$ where $t_{1/2}$ is time
taken for the profile to decay to half the maximum value. The broken power law
model provided a good fit to the first decay phase, as it was able to account
for the impact of chromospheric plasma evaporation, but it did not successfully
fit the second decay phase.
