One day, Max watched Ruby cut a strip of paper and tape it into a circle.

"Ball," said Max.

"No, Max." said his sister, Ruby. "It's not a ball. It's a link for my paper chain."

Max climbed onto the chair and reached for the circle. It was shaped more like a wheel than a ball. It rolled and then fell over.

Max reached for the rest of the paper. "Ball."

Ruby pulled the paper away. "I need this to make more links for my chain." she said. She cut another strip of paper. Ruby threaded the new strip through the first and taped it into a circle too. She shook her chain happily. "There! See, Max?"

Max didn't want a chain. He rolled up the sheet of paper, but it looked more like a tunnel or a telescope than a ball.

Ruby took the paper away. "That's mine, Max."

Max reached into the pocket of his overalls, looking for paper. Instead he found acorns.

The acorns rolled and scattered across the table, but they were too small.

"Acorns stay outside, Max." Ruby gathered them up and tossed them out the backdoor. While Ruby was busy, Max found an apple. He tried wrapping the paper around an apple, like a gift.

"Ball." said Max.

"You can't make a ball out of paper, Max." Ruby tried to explain, but Max didn't believe her. Ruby tried again. "You can't make paper perfectly round."

Max eyed her doubtfully. He took two of Ruby's round links and tried to build a ball.

"Why don't you go play with your Rock Crusher Dump Truck or your Jellyball Shooter Spider?" Ruby suggested with a sigh.

Max gave a sly smile and walked off. Ruby hummed happily, enjoying the quiet as she put more links on her paper chain. She finished with one sheet of paper and got a new sheet. Her paper chain dangled off the table.

Max returned with his Jellyball Shooter Spider. Climbing back on the chair, he aimed it at the sheet of paper.

"Stop it, Max!" said Ruby. "You'll get jelly all over my new paper."

Max didn't listen. His spider spat a jellyball in the middle of the fresh sheet.

"Max!" Ruby cried. "Look what you did! I can't make a chain with this!"

Max crumpled up the jelly-stained paper. It wasn't perfectly round, but he smiled and threw it across the kitchen. "Ball!"

Like Max, when I was a kid, I was convinced I could make a perfectly spherical ball just by rolling paper.