Mental math (and arithmetic tricks) are pretty important for scoring high on the GMAT (for MBA admissions). No calculator is allowed, and while you can solve by pen and paper, for a very time constrained test, tricks can be the difference between a good and great score.
It's also somewhat valued in the business / consultant crowd for talking through assumptions and making estimates of problems.
It's also somewhat valued in the business / consultant crowd for talking through assumptions and making estimates of problems.