A power is repeated multiplication: 2 × 2 × 2 is 2³, with base 2 and exponent 3. Folding a sheet in half again and again makes 2, 4, 8, 16 layers, and a square of beans with 4 on a side holds 4² = 16. To evaluate a numerical expression everyone follows one order: parentheses, powers, multiply and divide, then add and subtract. The crew opens the Puzzle Post with a folding puzzle and a bean square.