Video: Mental Math: Percents

July 29, 2010

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Today's video covers one of my favorite mental math tricks: calculating percents by starting with 10%, 5%, and 1%. It's powerful, and it's a great way to get you thinking more abstractly about all sorts of calculations--not just percents.

Some of the subjects covered in the video overlap with something I wrote several years ago. So if you prefer the text version, or you'd like to have it handy for review after watching, click here.



About the author: Jeff Sackmann has written many GMAT preparation books, including the popular Total GMAT Math, Total GMAT Verbal, and GMAT 111. He has also created explanations for problems in The Official Guide, as well as 1,800 practice GMAT math questions.

Total GMAT Math

The comprehensive guide to the GMAT Quant section. It's "far and away the best study material available," including over 300 realistic practice questions and more than 500 exercises!
Click to read more.