Forgive me for writing in English but there are no hebrew letters on the keyboard and it takes me twice the time to write a text when I am trying to figure out the right keys in Hebrew.

As a son to a Math teacher I remember my monther working a lot in the afternoons and evenings preparing lessons and checking exams. She was also complaining about her fellow teacher who teached gymnastics - that teacher had hardly any work to do once she finished her lessons in schools.

I think that teachers should be compensated in a way that is somewhat proportional to the time they spend working, whether it is at home or in school. I am not sure I have a suggestion of a good way to do that, but the way my mother was (not) compensated for the time she was working at home is really not a good one.

As for the calculation of "how much time a teacher really works in a week", I would say two things. One is that I thing you can not compare office hours to the hours of a teacher that stands in a class and has to handle 30-40 kids who do not necessarily want to study. It is difficult, unless you have a really cooperative class, which is not the common case. The second thing is that a teacher indeed works less days per year, but that is not a reason to justify a low salary. If you thing about it - he/she has no other choice. Meaning, a teacher who wants to work all year around like anyone else, does not have a way to do it as a part of his teaching job, or in any other way within the education system. The only way is to find a temporary job during the summer, but that job would probably have very little to do with his job thoughout the rest of the year.