I've heard that great inventors dream up ideas in their sleep.
I don't know if I dreamed my idea that night.
But when I woke up early the next morning, I had the answer to Jenny's problem.
And the answer wasn't under my nose.
It was on top of Jenny's nose!
It was Saturday, so we didn't have school.
I jumped out of bed and got dressed.
Then I dashed downstairs, and knocked on Josh and Jenny's door.
No one answered.
I knocked harder.
Finally Mr. Chen came to the door, wearing his pajamas and bathrobe.
Josh and Jenny stood behind him.
"Jenny!" I cried. "I figured out why you're having trouble in school!"
"Why?" asked Jenny, yawning and rubbing her eyes.
"Because you can't see!" I said.
"That's true," said Jenny.
"You woke me up, Iggy!
My eyes are still half-closed."
"No!" I insisted. "That's not it.
Remember when you tripped over the dog leash?"
Jenny nodded. "I didn't even see it."
"And you didn't want to call out numbers for the slide," I said.
"Because you couldn't read them."
Jenny blinked at me.
Mr. Chen was squinting too.
He looked confused.
"I don't understand, Iggy.
Jenny just got new glasses a few months ago."
"And they work perfectly," said Jenny.
"Yes, your glasses worked perfectly," I said.
"But you haven't been wearing your glasses."
"What do you mean?" asked Jenny.
"Remember when you said you and Sara had the same glasses?"
Jenny nodded. "Our glasses are the same color.
But our eyes are very different.
Sara can't see things close up.
And I can't see things far away."
"Right!" I said. "And you said Sara is having trouble in school now too."
"Yes," said Jenny. "So?"
"So your glasses probably got switched," I said.
"I think you're wearing Sara's glasses and she's wearing yours!"
By now Jenny's eyes were wide-open.
"I think you're right!" she said.
"We were both crying when we said good-bye.
So we had to take off our glasses.
They must have gotten switched then."
"Jenny," said Mr. Chen. "Can you go get your glasses?"
Jenny got her glasses and put them on.
Then Mr. Chen held up a newspaper.
"Can you read this?"
he asked, stepping back and pointing to a headline.
Jenny peered at the newspaper.
"No," she said. "The letters look blurry."
"Then Iggy is right!" said Josh.
Mr. Chen smiled. He looked relieved.
"Iggy, that was amazing!
You are a true problem-solver."
"Thanks!" I said, grinning.
"Let's have pancakes to celebrate," said Mr. Chen.
"After breakfast I'll call Sara's mom and dad and tell them about what happened."
That afternoon Jenny and Sara met and switched glasses.
After that neither of them had any more problems in school.
On Monday Mr. Bright, the inventor, came to our school.
He showed us some of his latest inventions.
One of them was a little umbrella for a dog.
You could attach it to a dog's collar so the dog wouldn't get wet.
Mr. Bright brought his dog onstage and showed us how it worked.
All the kids loved it.
"I know many of you are good inventors too," said Mr. Bright.
It seemed like he was looking right at me.
He probably loved my Pick-a-Number invention!
"I have been reading your invention ideas," Mr. Bright went on.
"And I've chosen one to be included in my new book."
Mr. Bright took a piece of paper from his jacket pocket.
I held my breath, waiting for him to call out my name.