Tips for calculating faster

Calculating Faster Speed in solving questions is of crucial importance if one wants to crack the MBA entrance exams. In fact, the only two skills tested in the Data Interpretation section are those of understanding data or interpreting information from raw data and calculating fast. In this article we will look at the basic groundwork you must do before you can even think of doing calculations involving complex divisions within 20 seconds. One needs to thoroughly learn: 1. 2. 3. 4. 5.

Tables up to 30 × 30 Squares up to 30 Cubes up to 15 Square roots up to 10 Cube roots up to 5

6. Reciprocal percentage equivalents up to 30 It seems like a very tedious and time consuming task. However, it is not as tough as it seems. Try this -- what is 7 × 8? I bet anyone would have answered 56. Now, what is 14 × 8? Even if I don't know the tables, I can understand it would be twice of 7 × 8, i.e. twice of 56, i.e. 112. Even though one did not know table of 14, one could have arrived at the answer within couple of seconds. Thus, except tables of prime numbers, i.e. 13, 17, 19, 23 and 29 all other tables till 30 can be done in this way if one knows the tables till 12. Reciprocal Percentage Equivalents Reciprocal percentage equivalents are the reciprocals of numbers 1 to 30 in percentages, e.g. the reciprocal of 3 is 0.3333 or 33.33%. Reciprocal percentage equivalent of 5 is 20%, of 6 is 16.66% and so on. Reciprocal percentage equivalents are an absolute must for one to crack quantitative section. Not only do they immensely help in division but also in many quant questions. So be sure to learn them by heart. You can also make and use flashcards to help you in memorizing them. Memorising Reciprocal Percentage Equivalents Let's see how reciprocals can be memorized. Almost everyone knows that reciprocal of 2 is 50%, of 3 is 33.33% and of 5 is 20%. If reciprocal of 2 is 50%, the reciprocal of 4 is half of 50%…25%? The reciprocal of 8 will be half of 25%...12.5%. Similarly, reciprocal of 16 will be 6.25%. Also if I know reciprocal of 3 as 33.33%, I can also conclude reciprocal of 6, 9 will be 16.66% and 11.11% respectively. Thus, from 1 to 10, one has to only mug up reciprocal of 7 which is 14.28% (simple two times 7 is 14 and two times 14 is 28…thus 14.28). If reciprocal of 9 is 11.11, reciprocal of 11 is 09.090909. Reciprocal of 9 is composed of 11s and reciprocal of 11 is composed of 09s. Reciprocal of 12 will be half of reciprocal of 6, i.e. half of 16.66%, i.e. 8.33%. Thus, we see that except for prime numbers, we can very easily remember the reciprocals of all others. Thus, effectively we need to mug up reciprocals of only 7, 13, 17, 19, 23 and 29. Some other numbers that can be remembered easily and the methods are: •

Reciprocal of 20 is 5%. Reciprocal of 21 is 4.76% and of 19 is 5.26%. Thus, we can easily remember the reciprocals of 19, 20, 21 as 5.25%, 5, 4.75% respectively.

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Reciprocal of 29 is 3.45% (i.e. 345 in order) and reciprocal of 23 is 4.35% (same digits but order is different) Reciprocal of 22 is half of 09.0909%, i.e. 4.545454%, i.e. consists of 4s and 5s.

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Reciprocal of 18 is half of 11.1111%, i.e. 5.55555%, i.e. consists of only 5s.

Thus, the work may seem to be a huge task, but if we use a smart approach, it is hardly anything. And compare it with the time it can save and the confidence it leads to. . . if any calculation has 9 in the denominator, I know for sure the decimal part will be only 0909. . . or 1818… or 2727… or 3636…, e.g. 84/9 will be 9.272727, and can be found out in a jiffy One can also calculate any fraction of the type (n-1)/n (n