I might suggest other lines of approach, such as Lazarus (I learned the
outlines of OO on Borland Delphi) which mixes coding with visual
application building, or the use of Arduino hardware which is cheap and
very much real-world, and is supported well on Debian. Python is the
preferred language there, which can be OO if you like. In my youth we
were pretty impressed with being able to draw ASCII penguins on fanfold
paper (you guessed, my first Fortran program), but I think today's
children want to see more in the way of results than a few lines of
text.