The Cookie Doubling Machine

Olu was an inventor. Most of her inventions were made of cardboard boxes, tape and big ideas. Her latest one had a flashing bike light on top and a label that said: The Cookie Doubling Machine.

"How does it work?" asked her older brother, Femi.

"You put one cookie in," said Olu, "and every hour, it doubles. One cookie becomes two. Two cookies become four."

Femi raised an eyebrow. "It's a box."

"It's a pretend machine," said Olu. "But the maths is real. Let's work out what would happen."

She got a big sheet of paper and drew a table. Hour zero: one cookie. Hour one: two cookies. Hour two: four cookies. Hour three: eight cookies.

"That's not very many," said Femi. "My lunchbox can hold eight."

"Keep going," said Olu. Hour four: sixteen. Hour five: thirty-two. Hour six: sixty-four.

Femi leaned in. "Okay, sixty-four is a lot of cookies. That's a full cookie jar."

Hour seven: one hundred and twenty-eight. Hour eight: two hundred and fifty-six. Hour nine: five hundred and twelve.

"That's enough for every child in my school," said Olu, "and the teachers too."

Hour ten: one thousand and twenty-four.

"Over a thousand cookies," said Femi, "in just ten hours? From one cookie?"

"That's the funny thing about doubling," said Olu. "It starts slow and then goes whoosh."

They kept going, just to see. By hour fifteen, the paper said thirty-two thousand, seven hundred and sixty-eight cookies. "That would fill our whole kitchen," said Femi, looking around. "We'd have to climb over cookies to get to the fridge."

By hour twenty, the number was over a million. Olu drew a picture of their house with cookies pouring out of every window, and a tiny Femi on the roof waving for help.

Mum walked in and read the table over their shoulders. "Doubling is very powerful," she said. "It's why I always say to wash your hands. Germs can double too, very fast, when they have somewhere warm to grow."

"Ew," said Femi. "I like cookie doubling better."

Olu added a new button to her machine. It was a bottle cap glued on with a label underneath. "Stop button," she explained. "Every good inventor thinks about what could go wrong."

Then she put one real cookie into the box, closed the lid, and waited exactly one hour. When she opened it, there was still just one cookie.

She broke it in half and gave one piece to Femi. "There," she said. "Now there are two."

⭐ The End ⭐