I have a question for those who have already been there, and those who are preparing to take the test soon. Did/are you using any special methods or techniques for calculations? I’m going to take it next year and have not started prep or practice passages yet. Calculators are allowed or even required when taking pre-reqs so I depend on them completely at this point.
I’m so pathetic right now that I can’t do long division at all, and can barely do multiplication on paper. Last time I had to do so was probably in high school, 20 years ago. Of course, I’ll be brushing up on all that stuff, plus basic algebra and math. However, I’m wondering if you folks have used stuff such as “speed math” or some other. I can see such techniques being useful and am considering purchasing a book on the Trachtenberg system and putting it to use. Anyone else thought of this or something similar?
I’ve always considered myself very good at math, but I’m personally struggling with those darn negative exponents (when it comes to electrostatics, magnetism, etc.). So I know what you mean. The TPR book I’m using for physics has a math review section in the back which I plan to study. I’ve heard EK also has something similar. While I haven’t looked at them yet myself, what I’ve heard is that they offer some tips on shortcuts, simplifying the math, etc.
Right, but once one has dealt with the exponent part, there’s still the two “mantissas” that need to be multiplied or divided. I’ve seen a few posts on SDN with techniques for simplifying calculations. For example, 1/17 can be simplified to 1/20 = 0.05 and since 17 is than 0.05 etc. If one has already eliminated two answer choices based on units or for other reasons, such quick computations can help narrow the correct answer quickly. Those kinds of tips work if one is good at quick computations such as 1/20. I think I’ve lost my ability even on this basic stuff.
I’ve been thinking about this for a while --> slow Friday at work --> got the itch --> ordered 3 books:
- Trachtenberg System
- Secrets of Mental Math
- Short-Cut Math
This could turn out to be 60 bucks well spent. Will report in a few weeks if these books are any good.
Hey dullhead!
I can attest to the book “secrets of mental math”
It’s a good refresher for basic arithmetic stuff. I like it, but you have to stick with the techniques or else you"ll forget them. Also, I found these apps on my iPad to be a big help. Just search for “mental math”
Hope this helps.
Good deal, thanks Julio.
I prefer the dead trees version though. I don’t own anything “i” and my cellphone is a flip phone from 2 centuries ago that is not even 0G 
I’m not opposed to technology but won’t upgrade unless its absolutely necessary. Not too long ago (4 years), I was running a box on Windows 98! If it ain’t broke and all that… Anyway, I am looking forward to receiving my dead trees versions of the 3 books.
Hi Dull
the deal is to eyeball any result that you expect or at least have an idea of the order of magnitude. Nothing will ever replace your brain. As far as calculations go, you should always know what value you expect. Simply round the numbers and use scientific notation because it simplifies all calculation.
On the mcat in gen chem II, you have equilibrium calculations to make. So for instance what is the square root of 1.8x10^-5. So do the calculation, you simplify somehow to have nice squares. I would turn that into 18x10^-6. Now you can do each part separately. root square of 18 is between 4 and 5 (18 is between 16 and 25). And root square of 10^-6 is 10^-3. End result about 4x10^-3.
Now the MCAT designs the operation to put you off but they can almost always be eyeballed. Either by using a technique like the one above, or by discard impossible answers.
I understand this doesn’t help much, but anytime you practice, even for your classes, always try to have an idea of what the end result should like. Then perform the calculation in the calculator. If you are off, it is very possible that you mistyped on your calculator. With practice you will become very good at quickly spotting the possible answer to a calculation, even if a priori it appears very difficult.
Redo - makes sense and I think I can manage all that without a calculator. Concept is the same as in the post I made earlier about the techniques explained on SDN. But I guess it would be good to have the additional backup of speed calc methods - that’s all. At one point in time I had started practicing so-called “Vedic math” techniques. I lost that textbook but maybe I’ll pick one up next time I go home. These things are useful as well as interesting. Could do without, maybe, but definitely don’t hurt.
Good advice all around here. There are so many resources available online, that it will make your head spin. I think spending a few weeks, after the semester is over, practicing certain calculations would be extremely helpful. I structured a refresher for myself before I started my postbacc (trig, scientific notation, etc).
An hour a day (or even 30 min), for a couple weeks will sharpen your skills, and give you a tremendous boost in confidence.
Dull
sure thing man. I guess the key is to practice early on and keep trying without a calculator. You will develop techniques on your own. Be familiar with powers of 10, some logs, a rounding techniques. There also some square techniques that can be useful.
But for sure, the only to do well enough, is to apply these anytime you have a chance.
Good luck bud.