  A didactic sequence of activities on some topics of Astronomy, related mainly
with the length and orientation of shadows cast by a gnomon, the movement of
shadows during daytime in different seasons of the year, and finding the true
astronomical North, is fully developed. It also includes a discussion of
observations from different frames of reference and of some topics in the
history of science to enrich a debate among students, as well as the
construction of a simplified model for the apparent displacement of the Sun,
and of a sundial, and their use as resources to discuss some common
misconceptions found in students. Multiple suggestions and clear guides are
given for teachers of secondary education to implement theses activities in
their classes.
