"What's that?"

He showed her a big chart he was creating. "This isn't a good way to do it. I'd have to copy it over and over again."

The sheet had a hand-drawn grid. Each square had a number. Some of the numbers were circled. "What is this?" Jane asked. "Oh, wait. I think I might know."

"It's about prime numbers. Do you know what they are?" Todd asked.

"Of course I do. They're the numbers like seven and eleven that can't be evenly divided by other numbers."

Todd was surprised. "So I was reading something this summer about prime numbers. Nobody's ever found a pattern for them. The larger they get, the fewer there are."

"That's right. They get so many new divisors."

"Right. So there must still be a pattern of some kind. Maybe it's a spiral, maybe a long rectangle. Maybe the pattern goes from high to low. See why I need to do this on a computer?"

Jane nodded. "So you can list a whole lot of them, mark the primes, and rearrange them."

Todd stared at her. "Gosh, Mom. I didn't know you knew about this kind of stuff."

"I liked math when I was your age, come to think of it. And before you kids were born I did the bookkeeping for the Jeffry family pharmacy."

"So could we move your computer out of the basement? I hate it down there. Maybe we could set it up in the living room."

"How about the dining room? We don't use it as often. Better yet, why don't we get you your own computer and you can help me move mine to my bedroom."

His eyes lit up like beacons. "You'd really do that? Buy me a computer? All my own?"

"It's an investment in your future, kiddo. Who knows, you might turn into another Einstein and support me in my old age. Now, what I came up here to tell you about is this. I had a talk with your math teacher this afternoon. You know that test you took at the beginning of school? "