--Bona al la encycla lorica.
The commoners of the world, including soldiers, are generally illiterate. Very little in society requires them to be able to read or write, or do math, and there generally aren't many texts around for them to read. The merchant class would have to be familiar with basic arithmetic, and track information in ledgers, and so know the basics of reading and writing, but only in meager ways (as a method of accounting); they do not know how to write most words, and are generally not familiar with literature.
Nobles, both male and female, are well-learned in the ways of writing and reading, as well as math, as would be necessary for them to engage in dialogue and espionage and in army logistics. Nobles oftentimes have scrolls and books across a wide range of topics, and one (minor) measure of a noble’s standing and power is the size of his personal collection of texts. Generally however, one crucial subject matter will be missing from their collection: that of the crafts (both mundane ones and ones concerned with spellshaping).
Spellcasters generally don’t have any need to learn to read and write, and so are mostly illiterate.
Spellcrafters may need to do math in order to work their craft, to a limited extent. But much of guild training is to ensure that they have internalized the steps of the tasks they do via rote memorization, so that little learning is necessary. Hence they too are generally illiterate.
Spellshapers need to be able to read and write to make records of their experiments, discoveries and inventions, and to make sense of the writings of their colleagues within the guild. They must also be fluent in the maths and sciences in order to do their work successfully. Hence the spellshapers of Lorica are by far the most erudite and well-educated of all the peoples in the world.