Talen made the quick computation in his head.

"We won't need much," said the youth, his brow furrowing slightly as he made some quick computations on the screen.

Ryan paused long enough to do a quick mental computation.

He calculated quick mental computations regarding time, distance and what he must accomplish.

Usually when an astronomer or a physicist did a quick computation, his first attempt was out by a factor of anything from ten to a hundred.

He unclipped the specialized slide rule at his belt and made a few quick computations.

I started doing some quick computations.

He had experience with the great Midwest flood of 1993 and he did some quick computations.

I timed the flash instantly and upon making a quick computation told my assistants that the tidal wave would arrive in 48.5 seconds.

Spock had been making quick computations and was turning to Kirk, too.