Pirates go to School by Corinne Demas, illustrated by John Manders

From chapters.ca: When pirates (and their parrots) enter the classroom, it's time to hang up their swords and have fun. They learn reading and math, see pirate treasure at show- and- tell, eat slimy squid, and hear stories of ships at sea. For pirates, going to school is as much fun as a game of "walk the plank"!