I've been amazed most of my life at how well some people can estimate time, distance, weight, quantity with precision and accuracy. My grandmother was able to estimate tablespoons, teaspoons, cups etc for baking and never measured anything.

I'm wondering of all these sorts of skills are active in the same part of the brain.

I would think so because I've read one study of monkeys and the economic concept of marginal utility where the researchers found that the monkeys would measure the marginal utility of one kind of food versus another (3 apples vs 6 bananas and so forth). So, if you can measure that I'm certain the brain can adapt to different units of measure in all conceivable categories.

https://en.m.wikipedia.org/wiki/Diane_Van_Deren, an ultramarathoner, had part of her right hippocampus removed to stop her seizures, which affected her ability to keep track of time and to read maps. Radiolab did a story on her a few years ago:

http://www.radiolab.org/story/122291-in-running/

I wonder what happens if you take away the reward. Neurons firing is related to energy. The reward has an associated amount of energy. Can it be something as simple as just distributing energy over time?