She pulled out her phone and quietly searched for the online solution guide. The screen glowed with the familiar layout of the textbook. There it was: Problem 14. She scrolled down, ready to copy the numbers, but then she paused. The site didn't just give the answer; it showed a diagram of the trains moving toward each other.
Masha sighed. She didn’t want jelly for a brain, but she also didn't want to spend her entire afternoon trapped in a world of locomotives and long division. She pulled out her phone and quietly searched
Petya didn’t look up from his notebook. He was scribbling furiously, his glasses sliding down his nose. "I’m not using a reshebnik (solution book), Masha. My mom says the brain is like a muscle—if you don't use it, it turns into jelly." She scrolled down, ready to copy the numbers,
"Wait," Masha muttered. She turned back to her own blank paper. She didn't copy the answer. Instead, she drew two little rectangles with steam coming out of them. She calculated the velocity, subtracted the overlap, and— click —the final number appeared in her head before she even saw it on the screen. She didn’t want jelly for a brain, but
Masha stared at Problem No. 14 on page 42. It was a multi-step monster involving three trains, two stations, and a very confusing amount of coal.
The classroom was unusually quiet for a Tuesday morning, save for the rhythmic thump-thump of Masha’s sneaker against her desk leg. On her desk lay the formidable "Mathematics, 4th Grade" textbook by Moro, Part 1.
When the teacher, Vera Ivanovna, walked by, she tapped Masha’s notebook. "Good work on the diagram, Masha. Most students just guess, but you’re seeing the logic."