The Housekeeper and the Professor

He treated Root exactly as he treated prime numbers. For him, primes were the base on which all other natural numbers relied; and children were the foundation of everything worthwhile in the adult world.

he believed that mistakes were often as revealing as the right answers. This gave us confidence even when our best efforts came to nothing.

they were almost off-putting.

The mention of money was probably nothing more than a smoke screen.

spill a great deal

"So you think that zero was there waiting for us when humans came into being, like the flowers and the stars? You should have more respect for human progress. We made the zero, through great pain and struggle."

"That's right. Eleven."
"An exquisite number. An especially beautiful prime among primes. And it was Murayama's number. Truly wonderful, don't you think?"

I could feel with my fingertip the elegant curl of the legs on the π, the certainty and strength of the dot on the i, the decisive way the 0 had been joined at the top.

He worked with precision and conviction, and even a kind of affection. His ironing seemed highly rational, with a constant speed that allowed him to get the best results with the least effort; all the economy and elegance of his mathematical proofs performed right there on the ironing board.

"And there's more to it: the numbers in the first group can always be expressed as the sum of two squares, but those in the second can never be."