You would think they would, especially given the fact that a lot of jobs in its own government require the ability to at least read and write at a basic level. And so does its school. Not everyone can divine the answer and mimicking the scratch marks of writing for what to put in an essay or field report.
But the maths thing, I suppose is why we've got our banking done with mostly goblins instead of predominately amongst ourselves. And I have actually walked him through that several times. After about the fifth or sixth, it starts to become annoying.