Numpty dad needs ma...
 

[Closed] Numpty dad needs maths help

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Work out [tiny 3][square route]125

Any help appreciated with the method to solve this please.


 
Posted : 05/01/2009 10:04 pm
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5


 
Posted : 05/01/2009 10:05 pm
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Cube root

What do you multiply by itself and itself again to give 125?


 
Posted : 05/01/2009 10:05 pm
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You can really only get there by guess work and averaging your guesses.


 
Posted : 05/01/2009 10:06 pm
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Cheers druidh, can see it now.


 
Posted : 05/01/2009 10:09 pm
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Or a calculator...


 
Posted : 05/01/2009 10:10 pm
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So it 3.34_ _ ??

Please tell me thats not a 12 year old's homework!


 
Posted : 05/01/2009 10:29 pm
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calculator? noob!
take the log of 125 (you have got a log book, haven't you?)
divide by three
look up the antilog
job done

tbh I don't know how it's currently taught without log tables, but looking at KS3 sites it looks like trial and error seems popular.

[url= http://www.gcsemathstutor.com/powersroots.php ]


 
Posted : 05/01/2009 10:35 pm
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So it 3.34_ _ ??

No, it's 5.


 
Posted : 05/01/2009 10:38 pm
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Doh! you work it back, not forwards 😳

I was trying to get 125 by multiplying ?x?x? =125, hence the 3.34xx


 
Posted : 05/01/2009 10:49 pm
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I was trying to get 125 by multiplying ?x?x? =125, hence the 3.34xx

Now I'm really confused. How did you get 3.34?

3.34 x 3.34 x 3.34 = about 37

Oh hang on.. 3.34 x 3.34 = 11.2, 11.2 x 11.2 = 125.

So 3.34 is the 4th root whatever that is called.


 
Posted : 06/01/2009 12:29 am