Divide by factor stages — halve, double, drop a zero, step by step
Gear Train — divide by breaking the divisor into easy factor stages, not by short division.
÷4 = halve, halve. ÷8 = halve, halve, halve. ÷12 = halve, halve, then ÷3. ÷15 = ×2, ÷10 (drop a zero), ÷3. You enter the method step by step — the value after each stage, in order — and each step unlocks only when the one before it is right. Five levels climb from ÷4 to mixed; the steps fade away as you climb until only a bare answer box is left, and a short timed boss caps each level.