Pracice your mental math. Also, you will find that there are ways to simplify the calculations. If you post an example of one you struggled with I will demonstrate.

I agree with everything said above. I just want to echo something that Brent said - don't worry so much about getting all of the problems within 2 minutes. Even on test day you will have some problems that you do not get done in two minutes.

You can take 3 minutes on some problems and less than 2 minutes on others and some may even be very quick for you. For example, I am quick and accurate on some types of Data Sufficiency questions that may take one minute, while on other questions I may take much longer.

Of those two things "quick" and "accurate" accurate is the more important of the two! Remember, as many experts have discussed in many different discussion threads, getting about 25 correct out of 37 on the Quant section can put you in the 75th 80th even 85th percentile.

Now in addition to all of the discussions about avoiding doing any really crazy sorts of calculations, let me add that when you do have to perform calculations that you should take them seriously and be sure to get the correct results. It is a shame to have the right approach to a question and then mess up the calculations. I certainly agree with Jim that mental math is a skill for the smaller calculations, I also think that there is much to be said for being to do calculations on paper in such a way that you get the right answer!

here is an article that I wrote where I discuss diagnosing the problem and performing the math https://www.beatthegmat.com/mba/2012/04/ ... at-success

Thank you so much for the help all of you were so helpful. I will definetly look into everybody suggestions.

I'm currently going over the OG13 and in the diagnostic test I am stuned by some questions that I think are really hard without a calculator. The questions are:

1. The product of all the prime numbers less than 20 is closest to which of the following powers of 10?
A)10 to the 9
B)10 to the 8
C)10 to the 7
D)10 to the 6
E)10 to the 5

2. If s and t are positive integers such that s/t=64.12, which of the following could be the remainder when s is divided by t?
A)2
B)4
C)8
D)20
E)45

Ok seriously i think these calulations are soooooo hard without a calculator. Can you guys give me some advice how to solve them easily without a calculator?

THis is my biggest problem in this section how to solve those equations without a calculator

And also how to understand the wording in the question.

I'm actually pretty good at math and I understand the solution just sometimes I don't understand the wording in the question cause it is tricky.