A positive integer. Divided by five, remainder three. Divided by seven, remainder two. Divided by four, remainder one. Smallest such integer greater than fifty.
“Read it back to me,” she said.
Caleb read it. His voice was careful. When he reached remainder two, he paused, as if the two might change its mind and grow a one. It did not. He finished. He looked at her for the nod that would let him proceed, and she gave it, a single dip of the chin.
“Tell me what you already know,” she said. “Not the answer. The shape.”
He chewed the inside of his cheek. “It’s one of those where the number has to fit all the rules at once. Like a lock with three wheels. My coach calls them stacks. You do one rule, then you make the answer to that rule go into the next rule. If you start with the biggest divisor it’s less messy. Seven is the biggest. So the number is two more than a multiple of seven. I can write that. I just couldn’t, before, because twelve wrecked it.”