There a a few definitions of math whiz that are commonly used in society. One is the ability to do numerical calculations in his/her head quickly and accurately, and the other is strong problem solving combined with abstraction skills. The first is an excellent ability to have in everyday life and allows that person to estimate numerical values at anytime with little effort.
The second skill however, is much more valuable, as that person is unlikely to be fooled by media logic holes (of which there are many), fallacies, and the ability to solve problems. Many employers will pay handsomely for a good problem solver, since there many people are not effective problem solvers. Many of the world's top CEOs are in fact former engineers or mathematicians, and are extremely wealthy from their mathematical skills.