"Scan" ... meaning not to look over hastily and superficially, ... but rather to scrutinize carefully and in great detail.
what the heck do we have for a brief look-over?
Scan, for one. Per M-W on line, the root meaning of scan involves looking over point by point. This can be done with great care or superficially. It makes no matter.
The root meaning of decimate did involve killing of one in ten but the other nine were sent off to other legions. The remaining quantity was zero. It's not unlike the trick question involving the ten crows sitting on the fence. Farmer Brown shoots one of the crows. How many are left on the fence?
The answer is, of course, none. The other nine flew away at the sound of the gunshot.
Still, there are those who bristle at the thought of decimating eliminating more than ten percent. The lion's share, on the other hand, is often thought to mean the largest portion, but in the original story it was all.
What was lost to the lion's share has been added to the decimated.
