I have designed quizzes for those who wish to test (and enhance)
their mental calculation skills. This is the one place where no
calculators should be used at all; everything must be computed
in your head (and yes it is definitely possible for each and every
question posed here) to maximize the training of the mind.
Have fun, and remember the clock is ticking. Peace.
Note: Results will be shown at the end of each quiz attempted; I
have also included explanations for some of the more challenging
problems.