For this chain-of-thought reasoning and answer, what was the question?
First find the total number of sheep by dividing the number rounded up by 90%: 81 sheep / .9 = 90 sheep. Then multiply that number by 10% to find the number that are in the hills: 90 sheep * 10% = 9 sheep.
 A: 9
Q: Carla's sheepdog rounded up 90% of her sheep, but the remaining 10% wandered off into the hills. If there are 81 sheep in the pen, how many are out in the wilderness?