Walt and Jesse watch in horror as Tuco brutally beats his henchman, No-Doze, to death over a minor slight.
The episode's title is layered with meaning, initially representing the cold, hard math of Walt’s "exit strategy". In a moment of clinical detachment, Walt calculates that he needs exactly to provide for his family after he's gone—accounting for college tuition, the mortgage, and a decade of living expenses.
Skyler, feeling abandoned and overwhelmed by Walt’s constant disappearances and her sister Marie’s kleptomania, finally unloads her frustrations on Hank in a raw, emotional breakdown.
In a classic display of the show's dark irony, Hank unknowingly sends Walt a photo of a crime scene featuring Tuco's deceased henchman, Gonzo, thinking it will amuse his brother-in-law.