P% of V = V% of P — swap to the friendly fraction, then apply it
Percentage Swap — turn "P% of V" into the easy fraction form.
For 64% of 75: swap it to 75% of 64 (P% of V always equals V% of P); 75% = 3/4; apply it: 64 ÷ 4 × 3 = 48. You enter the method step by step — the swapped pair, the fraction it equals, then the answer — and each step unlocks only when the one before it is right. Five levels ramp the fractions from halves and quarters up to fifths; the steps fade away as you climb until only a bare answer box is left, and a short timed boss caps each level.