How does Jem solve Scout's problem with Walter Cunningham in Chapter 3 of To Kill a Mockingbird?

Scout was busy rubbing Walter Cunningham Jr.'s nose in the
playground dirt as payback for the trouble he had caused her with Miss Caroline when Jem
came by. Jem got his sister to stop fighting with Walter, coming up with a friendlier
plan: They would invite him home for lunch instead. Scout finally cooled off, and
Atticus welcomed Walter, talking "together like two men." Walter obviously got very
little to eat at his own home, because he "piled food on his plate" once Calpurnia had
served it. Scout also got a lesson on hospitality from Cal after making fun of Walter's
habit of drencing all of his food in molasses, and Scout was soon able to call Walter
her friend.