Hey Lindsey,
First of all, congratulations on a 670! If there's one thing that communities like BTG do a little irresponsibly, I think, it's putting these undeserved stigmas on scores that are actually really impressive accomplishments. What's that, a little above the 80th percentile? So better than 4/5 of examinees, nearly all of whom have graduated from college and feel qualified to succeed in higher education? I know we all dream of scores that start with 7, but in doing so I hope we don't forget that among the pool of self-selecting GMAT test-takers there's no shame in being more than a standard deviation above average!!
Now, that said, I certainly agree that you can improve and I admire your commitment to doing so. And with this as a starting point (at least an "official test starting point") you're in pretty good shape.
I have a couple thoughts that I think might help given what you wrote:
1) It sounds like most of what you've studied has been at the "content" level. But I recently heard a pretty enlightening quote from one of the higher-ups at GMAC, those who administer the test, that "we're not testing your math skills or your verbal skills; we're testing your reasoning ability and higher-order thinking. If you don't know algebra or geometry well enough you'll get questions wrong, but that's not what the questions are about. We use those topics to set up questions that assess your ability to think logically and critically - that's what we're really testing."
Now, what I'd take from that is that it's not enough to know "all the problems in the OG". The authors of the test know exactly which problems are in the OG, and their mission isn't to reward you for memorizing each individual problem setup and having a specific method for it. Their mission is to see if you can really think; to see if you can see a unique-looking problem and use the skills and frameworks that you've studied to make sense of it.
So I'd challenge you to "think like the testmaker". As you see problems, ask yourself how the GMAT authors could make them harder or just "different". When you're reviewing concepts ask how they might be able to turn them into unique questions. Challenge yourself to see concepts and question types from multiple angles and not just the A-to-Z way that that problem happened to be written.
So, for example:
-At this point you know "number properties": Even/Odd, Positive/Negative, Units Digit. But while a 67th percentile question may ask you to employ Odd/Even number properties, a much-harder question might ask you to use the real guiding principle behind those properties, which is that numbers often behave in patterns. It may not test a property that you could memorize or have seen before, but you can employ the idea that "when in doubt or when dealing with large numbers that I don't want to calculate, try to find patterns". Here are a few examples:
https://www.beatthegmat.com/remainder-q- ... 61475.html
https://www.beatthegmat.com/mba/2010/09/ ... ries-day-5 (referring to the problem/solution on that day...not the "new problem" that day)
Now, I choose both of those examples for a second reason - they're two wholly-different looking problems that both employ the same exact (and kind of unique) number property. And that's what I mean by "ask yourself how they could create a new problem or make this one harder". If you can anticipate ways in which they can twist one problem to make you use the concept in a different way, your knowledge base is much more flexible. So "they asked me for the tens digit so I..." could become "they gave me the tens digit and I...". If you've only learned from A to Z they can trap you by making you go from Z to A. So try to understand concepts both ways, or really from a 360-degree view. My favorite OG question these days is the one that goes:
For positive integers m and n, when m is divided by n the remainder is 14. And the result of m/n = 65.4. What is the value of n?
People abhor this problem. But it's classic GMAT - it calls on you to recognize that you can do not
-evenly-divisible division three ways: (so let's use the example 11/4)
Integer quotient and remainder (2, remainder 3)
Integer quotient plus mixed number (2 and 3/4)
Decimal quotient (2.75)
In each case, the 2 remains the same. So in the given problem, we don't really need to deal with 65. We know that if m/n = 65.4, then if they tell us the remainder is 14 the answer in that "quotient-and-remainder" setup is 65, remainder 14. And how do we relate the remainder to the decimal of .4? It's that middle way to express it - the mixed number. We take the remainder and divide back by n, and that gives us the decimal places. So 14/n (the remainder divided back over n) gives us 0.4: 14/n = 0.4
14 = 0.4n
140 = 4n
35 = n
And what the GMAT learns from testing this problem is whether you can see that relationship between remainder and decimal point. They're making you reverse-engineer the concept of division. If I told you to divide two numbers and I asked for any of those three formats for the solution, you'd do it without thinking. But what makes this a critical-thinking exercise is that they didn't ask that; they asked you to take the results and use them to "create" the process. They asked you to go from Z back to A. And that's more of a conceptual/strategic skill than it is a "content" skill.
I'm probably losing the whole enumerated list thing by ranting on point #1, but the point really is this - think like the testmaker. Don't learn one method to solve one problem. Think about ways they're asking you these questions and how they can tweak them to ask them in different ways. Learn a 360-degree view of concepts and question types, because harder questions have to be written in a way that rewards those who can really think.
2) I promise I'll make this point a quicker read! But the other thing that I took from what you wrote is that you fear the test a little bit. The 1,000 flashcards, the capitalization on "ALL" the OG, the focus on thoroughly covering content...all classic signs of someone who went into the test "hoping to remember" and probably worried about pacing, trying to gauge question difficulty for an idea of 'how I'm doing', etc.
Now, that's pretty normal, but recognize that test stress and fear-of-the-GMAT are typically pretty counterproductive. So I'd recommend:
-Have a "contingency plan" for pacing. Know that if you fall a couple minutes behind your target pace, rushing through multiple questions to get back on track probably means that you'll miss a few questions that you should get right. Know also that you're going to miss questions - everyone does. So you may want to plan in 3-4 "I pass" questions on which you STRATEGICALLY guess quickly to save yourself time and confidence. I think you can manage the test better (but I don't know...was pacing or just that "I have to rush" feeling a problem?) and allow yourself to relax and do the things you do well, well.
-See the GMAT "traps" (negative numbers and nonintegers as those exceptions on DS problems; questions with multiple variables that bait you into picking the value for x when they really want the value for y, etc.) as "weapons". You GET TO use those as ways to beat the test; you don't "have to remember" those or the test beats you. You know the test, so try to see that knowledge as an asset you have in your favor instead of something that creates apprehension because you worry that the test will use it against you.
Anyway, just one man's opinion on how you can improve. I hope that helps...
