Lesson: QC Strategy - Approximation

Comment on QC Strategy - Approximation

3003/9009=1/3 then 3003/9047 should be more then 1/3 how it is less than 1/3
greenlight-admin's picture

To show why making the denominator bigger makes the value of the fraction smaller, consider this extreme example with a super huge denominator:
This fraction simplifies to 1/100000000, which is MUCH smaller than 1/3.

For more on this strategy see https://www.greenlighttestprep.com/module/gre-arithmetic/video/1067 (the related concept starts at 3:00)

Thanks for this!

I am enjoying learning your tricks... I am planning on barely using the calculator if not at all... Thank you..
tahmina.mm's picture

your tricks are just amazing.

very helpful tips and tricks..makes life so easy...thank you so much

Learned something new today! thanks
greenlight-admin's picture

Glad you liked the lesson!


Hello sir,
I am really finding your videos useful but I am not getting how to access all the questions related to one particular topic.Kindly guide me.
greenlight-admin's picture

Under most video lessons (like the video above), have a Reinforcement Activities box (like the one above) with links to practice questions related to the concepts covered in the video lesson.

Here's a better example: https://www.greenlighttestprep.com/module/gre-arithmetic/video/1071

Does that help?


Brilliant! I am very pleased that I found...I need to kick ass on this exam
greenlight-admin's picture

Glad you like it


Very educative, please I want find out how 2006/5987 is greater than 1/3
greenlight-admin's picture

We know that 2006/6018 = 1/3
So, 2006/5987 must be GREATER THAN 1/3

For more on this strategy, watch https://www.greenlighttestprep.com/module/gre-arithmetic/video/1067 (starting at 2:57)


I could find only one question in reinforcement practice first bullet. Please help, what I did wrong?
greenlight-admin's picture

Sorry, but I'm not sure I understand your question.
Can you please rephrase it?

what is the reason when using Reinforcement Activities practices, the practice is not highlighted any more and I couldn't use that link for second time!!
greenlight-admin's picture

Once you visit a linked practice question, the link appears lighter so that you know which questions you've already answered.
That said, you should be able to use the link as many times as you wish.
I just checked, and I can do that.

What happens when you click a link a second time?

Thanks I got it.

Whenever I see big numbers that you need to multiply and the calculator can't compute them (i.e. says "error"), I just use smaller numbers. For example, in the last QC question, side A is 131,047 X 480,111. I break those down into more manageable "tasty" numbers that the calculator can compute. I call this the "Feed the Calculator" technique. Give it some tasty numbers that it will find utterly delectable. (You like that witty technique? I do! Nobody has come up with it except myself!) So I would convert those numbers to 131.05 and 480.1. 131 and 480.1 are ok too. Do the same for side B and you will still get answer A.
greenlight-admin's picture

Great idea!!

I liked the "bigger than" notation concept,
greenlight-admin's picture

I'm glad you like it!

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