Ten-year-old Filip hated two things with equal passion: boiled carrots and his math workbook. Every afternoon, the orange workbook—officially titled Pracovní sešit matematika 6. ročník, 1. díl —sat on his desk like a tiny, geometry-shaped jailer.

He unfolded it. There they were: answers to every single exercise from page 8 to page 45. The fractions, the decimals, the word problems about trains leaving stations—all solved.

By the end of the year, he didn’t need the solution sheet anymore. But he kept it. Folded carefully. Tucked inside the back cover of Pracovní sešit matematika 6. ročník, 1. díl .

But then came the test.