[caterping]

Teachers don't have a "yearly salary" per se ... instead, they have a number written on the contract that indicates what they'll be paid for the school year.

When someone says, "teacher $X makes $Y per year", it means that $Y is that number written on the contract for the school year.

Note, given that

* most teachers spend a couple of weeks after the school year ends tying up loose ends from the year and organizing themselves for next year,

* and then simply need time to decompress from dealing with a large number of kids every day for so long,

* and also that they spend the weeks before school begins prepping for the new year and doing professional development,

there's not really much time in between to get another full-time temporary job to supplement their income.