Gorlog's teeth!" Erak exclaimed, stunned at the numbers. "How many are there?"
"Ten thousand, maybe twelve," Halt replied briefly. The Skandian let out a low whistle.
"Are you sure? How can you tell?" It wasn't a sensible question, but Erak was overwhelmed by the size of the horse herd and he asked the question more for something to say than for any other reason. Halt looked at him dryly.
"It's an old calvary trick," he said. "You count the legs and divide by four.

Autore: John Flanagan