You always need not solve exactly and till the end but till u get the correct answer.
Ø Just do this calculation 58.88 – 25.12 – 11.03 and mark ur answer .
Ø How did you do ? The answer is 22.73
Many of you have done the whole subtraction and the wiser ones have only subtracted the decimal part and checked the option. Lets see the decimal part .88-.12 - .03 = .73 and in the options you find 22.73
Ø Now try this one 76.89 – 63.05 – 11.11 = ?
e. None of these
v Have you got 3.73 very quickly I suppose. But here it is wrong. Answer is 2.73 . None of these. My point in this illustration is that sometime we depend very heavily on making shortcuts and come up with wrong answers. It is always better to be cautious and also know why there is short cut, and when it will not work. So here it does not work because the answer can be hidden in the option None of these and the examiner can tempt you to mark some other by showing a matching indication. But if there was not this None option, then it would have been okay. So take care of it.
Ø Mark the nearest answer
o 27.012 = ?
o 34.005 % of 549.99 = ?
v What you should do when calculations are of such type. It does not matter if it is 27.01 or 27 when u will square because the difference in answer will be minor. Lets see 272 = 729 and 27.012 = 729.54 Look 0.54 is not a thing which will matter in front of 729. Just see how small it is = 0.54 / 729 = 0.07%
v Similarly it is better to take 34% of 550