h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Excellent - great article. It even worked (once I'd mastered the ability to double and half numbers without making simple errors!).



The Apprentice

Thanks TA

"It even worked"

Well, that's a bonus!

but it was so much quicker just to multiply the numbers in my head!


interesting stuff though

Sssh - don't say that - they'd never have published it!

It is neat how you can do little math tricks to simplify calculation.

Take 16 *8 for example. 16* 8 = 128
If you double the 16 to 32 and halve the 8 to 4 you still get 128, and if you double the 32 to 64 while reducing the 4 to a 2 then you get 64 *2 = 128. You just reduce the one to its lowest denominator (if I remember my math correctly) while raising the other to its largest # by an equal amount. Numbers like 60 *4 are easy as well. 6 * 4 = 24 then you just add back the 0 so 60 *4 =240.

Interesting.

TRiG.

Hi TRiG

It's something every schoolchild should be taught, in my opinion. Not that it's a practical method (because it isn't), but it's a simple introduction to number theory.

Icy