wow-- you are really coming up with some unique sentences! It took me awhile to understand this myself. I would guess that this passage was written by an hispanic person. Calabash is a slang word that means the head. So the author is saying, in kind of a poetic, indirect way, that he doesnt like mathematics, that algebra is way beyond him and that he expects to learn no more than the multiplication tables. So, if you go to school in the USA today that means he expects to learn only up to 12 x 12 = 144.