Count the rice, one grain a time, until you reach 100 million. This was the homework a primary school teacher assigned to her class of fourth graders in Foshan, Guangdong province, Nanfang Plus reported Thursday. But to many parents, the task seemed an impossible ask.

“If you were to count five grains of rice per second, it would take you 231 days,” commented one netizen under screenshots of the assignment shared online by parents.

But the teacher apparently didn’t expect the assignment to be taken so literally. “It’s just a game the students can play with their parents,” she told Nanfang Plus. “With their knowledge, they can figure out how to estimate 100 million grains of rice.” The teacher added that most of her students had enjoyed the assignment. (Image: Sixth Tone)