[email protected] wrote:Hi, I'm South African (english first language and Math Major) and have just received my GMAT OG (plus reviews x 2) from Amazon.

I read on https://www.mbaapplicant.com/gmat_strategy.htm that you need a prep book? Is this needed? Is there so many "tricks" that I won't pick up through the OG's?

A prep book may not be necessary--there are a lot of great free resources available here, check out: https://www.beatthegmat.com/wiki/

Prep books are certainly helpful for self study, but there have been several cases where people have just relied on OG and did well.

One thing you can do to see whether it's worth investing in more books is to take a GMATPrep test, available for free at MBA.com. If you are comfortable with your score on this test, then you may be fine with just OG.

FYI don't expect to pick up actual testing tips from OG. They just give you the basics - questions and the official explanations. But the official explanation is not always that clear, nor is it always the best or most efficient way to tackle a problem. The test makers aren't in the business of helping people get better at taking the test, they're just in the business of providing the test, and this focus shows in the materials that they produce.