More and more, medical and academic studies are showing that doing so-called "brain exercises" helps to keep a person alert and possibly avoid Alzheimer's disease or dementia as they get into the later years of life. Doing mental numerical exercises is a particularly effective technique, according to many researchers. In this regard, how to do mental arithmetic then becomes important.
Mental arithmetic puzzles come in a wide variety of forms and varying skill levels. Sometimes, they require nothing more than a simple mental addition of two or three numbers in an array of them that will give a person a stated goal number. Doing several or more of these short puzzles in one sitting is likened to making the brain do pushups or sit-ups, to use an exercise analogy.
Another important aspect of these sorts of arithmetic exercises is that they're timed. As your brain gets better and better at processing the puzzles, the theory goes, neurological pathways are strengthened, and the brain gets better at handling many other tasks not related to actual number crunching.
In almost every course of mental arithmetic calculation, simple addition of one-digit numbers is first done, and then the figures are increased as a person doing such exercises gets more proficient at doing them. This can be done for all four basic formulas, including division. Eventually, complex equations are done, with a person being trained to picture the equation in their minds while the do the figuring.
Mental arithmetic can be a great way to help get a mind mentally alert and active through all stages of life. It certainly doesn't have to be the case that senses and mental agility need to dull as a person ages, too. Crossword puzzles (or Sudoku) and doing mathematical calculations in the head are both excellent processes for ensuring a quick wit and a sharp mind.