Divide by 9

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Category: Miscellaneous Miscellaneous
Published: 15 September 2008 15 September 2008
   

 

 

Another article on quick head calculations explains how to quiclky divide a number by 9.

 

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The rule of 70

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Category: Miscellaneous Miscellaneous
Published: 15 September 2008 15 September 2008
   

An article on the old financial rule of 70. It explains how it works and introduces some new "rules" of my own:)

 

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Square Roots

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Category: Miscellaneous Miscellaneous
Published: 15 September 2008 15 September 2008
   

How to calculate square roots in your head... no aspirin required.

 

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