He tried one. Got it wrong. Checked the answer. Saw the step he skipped (converting to improper fractions first). Tried again. Got it right.

That weekend, Leo hit the wall again. Level E, Set 14: mixed numbers. ( 2 \frac{1}{3} \div 1 \frac{1}{2} ). He felt the old panic. But now he had a new rule: Do not fight the worksheet. Use the answer booklet as a map, not a cheat.

“Was it?” she said. “Let’s use the Kumon trick. Don’t look at the whole mountain. Look at the first rock.”