Saturday is a beautiful day, but Tom is stuck painting Aunt Polly's fence. He's even jealous of Jim's chore of going to fetch water, which would at least give him the chance to talk to others at the well. Tom tries to convince Jim to trade tasks, but Jim says Aunt Polly has already told him not to let Tom leave the fence. Jim resists Tom's offer of a white marble in exchange for painting some of the fence, but gives in when Tom promises to show him his sore toe. Aunt Polly immediately arrives and forces Jim away with a smack from her shoe.
Tom always wants what he does not have, even seeing the chores of others as preferable to his. In trying to get what he wants, Tom doesn't worry about how he might get Jim into trouble. Yet Tom isn't mean-spirited towards Jim, however, while Aunt Polly is. She hits Jim in her frustration with both Tom and Jim. Her harshness towards Jim makes clear the cruelty endured by blacks in St. Petersburg.
Tom continues whitewashing the fence when along comes Ben Rogers, eating an apple and playing at running an imaginary steamboat. Tom pretends to be wholly absorbed in his task. When Ben teases him about having to work, Tom contends that whitewashing is a privilege, and one that Aunt Polly would only trust to him. Ben begs Tom to let him try, which Tom does, but only after Ben agrees to hand over the rest of his apple to Tom.
Play-acting is another shared activity of boyhood that Tom engages in with his friends. While friends with most of the boys, Tom is also more clever than them. He realizes that he's not alone in wanting what he does not have, and manages to make his difficult chore look like a privilege to Ben Rogers.
Tom plays this trick on other boys for the rest of the day. He amasses all sorts of treasure—a dead rat on a string, marbles, a chalk fragment, and more—and gets the boys to do so much work for him that the fence has three coats by quitting time. He feels delighted, rich, and optimistic about the world.
Tom does not share his newfound wisdom as a moral lesson to Ben, and instead uses it to further exploit his other friends. Tom has discovered the useful business model of many a wealthy adult: make others work for you in exchange for invented notions of wealth and privilege.