He distributed the negative: 5y³ - 3y³ = 2y³. 0y² - 4y² = -4y². -2y - (-y) = -2y + y = -1y. 1 - (-6) = 7.
His hand hovered.
The next morning, she returned the graded practice. Red checkmarks on 1, 3, 4, 5, 6… and a small, perfect check on #7. He distributed the negative: 5y³ - 3y³ = 2y³
The answer key for “7-1 Additional Practice: Adding and Subtracting Polynomials” sat face-down on Ms. Kellar’s desk, a silent judge. 1 - (-6) = 7
Leo smiled. The real answer key wasn’t on a separate sheet of paper. It was in the careful, error-by-error process of building his own. Red checkmarks on 1, 3, 4, 5, 6…
Ms. Kellar walked back in. “Time’s up. Pass your papers forward.”
Now, during the last five minutes of class, Ms. Kellar had stepped into the hall to take a call. The answer key was right there. One quick flip. A single glance.