The expression "not that bad a place" or "not so bad a place" is an informal shortening. " Without the "a" the meaning changes or becomes unclear. It might sound like you were trying to say "School is a bad place" but didn't know how to use grammar.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Doctor DThe full, expanded phrase is "School is not that bad of a place."