is John. They're both good students and ambitious." "Ambitious to get out of the house, you mean?" "Aren't you anxious for that, too?"

"Sort of. But I have longer to wait than you do. My John is a year younger than your Todd. And what is Todd doing this summer?"

"He's looking into colleges on the Internet. He'll only be a junior this fall, but wants to go somewhere where they teach higher mathematics. He's also moved his bed and desk into Mike's room because it faces the street and has better light. He's still working on breaking the code on prime numbers."

"Prime numbers? I've heard of that. But what are they?" Shelley asked.

"The ones that aren't divisible by anything. One, five, seven, eleven, thirteen, seventeen, nineteen, twenty-three, and so forth. He has a fancy grid program and put in numbers up to twenty thousand; he left all the ones that can be divided by two in black, and highlighted the ones in red that can't be divided by three, five, seven, and so on."

"So what's his conclusion?"

Jane sighed. "He doesn't have one yet. But the higher the numbers the less frequent they are. He's trying them out on all sorts of different grids to see if he can find a pattern. So far he hasn't."

"He's a dogged kid, isn't he? I remember when he was obsessed with building the biggest thing possible with Legos."

"But, Shelley, that cost me the earth and created huge storage problems. This costs me nothing and if he ever finds out the secret to prime numbers, he'll become rich and famous,"Jane said with her fingers crossed and wearing a big grin.

"So Katie's gone, Todd's obsessed, and Mike's in graduate school in Indiana for the summer. It must be a lot quieter at your house. I envy you."

"Thank you. I can't remember you ever saying that," Jane said, still smiling. "I'm also a better driver than you, but you'd never admit that."