Like everyone has pointed out. I would like to know how a 13 year old street urchin with no schooling learned to read and write. He also knows math? Where'd this education come from?
from survival? his math is incredibly simple, meaning you don't actually need education to learn that 2 2=4. Reading and writing can also be self taught, although much harder then raw logic of math.
Hmmm maybe make him go into a commoners bookshop to buy books on arithmetic, science, politics, social studies and on his native language ...maybe like a dictionary.