Dimensional analysis is a powerful tool for anyone to have. It can help you work out whether a 5 ounce can of soup that costs $0.99 is a better deal than an 8 ounce can which costs $1.54. (It's the 8 ounce can, which costs 0.55 cents less per ounce.) It can also tell you if you have the units wrong on your homework problem, and probably therefore have done the problem incorrectly. Practicing scientists use dimensional analysis all the time in their work, as well, but really, dimensional analysis is a tool everyone ought to keep in mind. And usually does -- I bet you could've worked out the soup can thing without reading any of the other stuff in this whole section.