Picking up numbers

Question

I know that quite a few people solve questions by picking up numbers which can be sometimes a very quick way to find a solution. However, this can lead to false answers.

I've got several questions:

1) Are there some techniques for picking up numbers?
2) Is it safe to assume that every single GMAT question can be solved in a traditional way under 2 minutes?
3) What's your opinion on and experience with picking up numbers?

I address this questions mainly to math gurus and people who are good at math.

Thanks.

shaselai · Answer

1. NEVER pick 1 or 0. Pick low numbers like 2,3,4 AND their negative counterparts if applicable - most answers can be found by a combo of negative + integer/fraction. Also, make sure the number you are picking not being shared much by the choices as sometime it could result in confusion. For example, if the question has 2*X or something like that it is probably not a good idea to pick 2. Not saying it wont work but it is possible you might need to repick.
2. yes if you know the trick to it. If you see yourself doing long mult/division time consuming counting then you are doing it "wrong" in terms of the "correct way". Plugin is sometimes easier than algebra since you *could* make mistakes on algebra but it is dependent on the test taker though... Also common sense goes a long way in eliminating answers too
3. I dont like algebra - i can do it sure but i almost always try to do pick numbers.

here's a "trick" i learned when picking numbers FROM answer choices.
For example the answer choices are:
1
3
5
6
9
If you plug back the number instead of solving try to pick choice B or D . Because what happens is if you picked D and the answer is too low then you pick B - this way if B works - great, if not you know it is A or C! Becareful, use this only when the answers are in some kind of order.! kudos!

shrouded1 · Answer

1> Nothing in general. Depends Q to Q. For Eg. In a question involving exponents, you might want to split thinking between numbers <0, between 0 and 1 and >1. So it really depends on what situation you deal with.

2> There is always a trick to make it happen under 2 minutes. I would much rather bank on doing say 80% or 90% of the Qs in about a minute and a half, so that for the ones where the trick doesnt come to you, you can afford to spend more than 2 mins.

3> It only ever worked for me when I already have a hunch about the answer and am just looking for proof. As a rule, always try the algebraic method first.

nonameee · Answer

Thank you for your responses. So far I believe that it's better to solve the problem rather than to try to pick up numbers.

The problem with picking up numbers for me seems to be that I cannot find a sort of a pattern in this method. And in the the end it creates more confusion than use.

onedayill · Answer

Nothing as such, just try to practice few of the questions.
Always remember that you substitute both +ive and -ive numbers.

Picking up numbers

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