I'm current enrolled in MGMAT in-person live course and when I was introduced to number properties and data sufficiency the first couple weeks, it was quite daunting. Those problems took me an average of 3-5 minutes, way more than the 2 minute time frame. The problem with DS is the unfamiliarity of the question type. This is the reason why you can't quite figure out what it's really asking with any sort of speed. Also, number properties in itself is also unfamiliar to most test-takers. No one, except Math geeks, really goes around thinking Odd+Odd+Even*Odd = Even on a day-to-day basis, before being introduced to the GMAT. The key is to keep practicing DS questions and ingraining NP rules so that these rules become second-nature on test day.

Akuma,

I agree with the Number properties, they need to be ingrained. I am far from that after a week in.

What other guides within MGMAT were helpful for your quant prep?

I saw that you answered my tutoring question as well and I am on the same page. I need to give myself more time within the guides.

Thank you for your insight as well as experiences from the live courses.

~Blake

Regarding Number Properties, it's a lot more important (and useful) to know that a rule exists than to memorize the rule itself. Knowing that "Odd * Even = Even" and "Odd + Even = Odd" isn't really necessary, and memorizing it is fraught with error (look back at those two statements - the only difference is the * vs. + disctintion, which leads to opposite results...it's tough to memorize that with 100% accuracy). If you just know that "every time I do addition, subtraction, or multiplication with odd and even integers, there is a rule that will hold," you can prove that rule with small numbers. Take multiplication...if you know there's a rule, you can try with 1 and 2: 1 * 2 = 2, or odd * even = even.

Your point on "properties need to be ingrained" is well-taken, though - the more you learn, and not memorize, these rules by proving them or testing them for yourself, the more they'll become second nature. Like I said, though, I've seen people have a lot more success, and proceed with a lot more confidence, by focusing on proving the rules to themselves than by trying to simply memorize them.

Best of luck with those Number Properties...I think you'll learn to enjoy them!

The only thing that has really helped me with DS is to maintain the same approach for every problem and avoid the temptation of doing things in your head. The problems you get right you should attempt to get right all of the time and the problems you get wrong you should get wrong all of the time. This way you can hone in on the weaknesses and eventually get those problems right consistently. Hope this helps.