The top-selling book on Amazon at the moment comes with a completion certificate for readers that says: “Great Job! You’re #1.”

It’s a 320-page activity book for 3- to 5-year-olds, designed to help them master shapes, colors and letters of the alphabet, and it’s recently surged ahead of best-selling novels like “Where the Crawdads Sing” and “Little Fires Everywhere.”

“So much fun! And is helping along with our Covid-19 home schooling!” one customer wrote in a five-star review of the book, “Big Preschool.”

It’s no surprise that such books are suddenly selling in vast quantities. As schools across the United States shut down in an effort to slow the spread of coronavirus, millions of parents find themselves cooped up with bored, restless children. And on top of feeding and entertaining their offspring, parents are suddenly expected to educate them as well.