The Original Schrödinger's Cat Revisited: Shut Up and Calculate

“Shut up and calculate” is commonly associated with a pragmatic attitude toward quantum mechanics: instead of debating interpretation, calculate observable predictions. This paper applies that instruction directly to the original Schrödinger's Cat. Schrödinger specified “a tiny amount” of radioactive substance, an equal probability that one of its atoms decays or none does within one hour, and “the first atomic decay” as the decisive occurrence. These statements contain two quantitative questions: What is the amount? What is the probability of the first decay? Using Schrödinger's Quantity and the First Decay time t₁, these become: calculate the number of atoms n satisfying the one-half probability condition, and calculate the probability associated with the first decay occurrence. No interpretation of the cat is required for either question.