These days we have become so much dependent on the mechanical devices that we have almost forgotten how to use our mind. We need calculators (if not computers) to add our shopping bills. Daily life tosses plenty of math problems our way. Of course, normal calculation can get boring. Here’s the secret: Tricks & Shortcuts. Mental calculation comprises arithmetical calculations using only the human brain, with no help from calculators, computers or even pen and paper but easily and quickly.