Hermione and Draco groaned simultaneously, Hermione from impatience and Draco from confusion and frustration. Hermione jabbed her finger angrily at the circle once more. "It's not that hard to get," she muttered, "pi is the number of radius lengths in a semi-circle."

Draco stared at the circle, willing himself to understand even though it was futile. "I don't get what this has to do with food." The mess Hermione was trying to explain to him was utter nonsense. There was no point to it. Stupid, incoherent muggle math. Why had he ever asked Hermione to teach it to him?