[etoys-dev] Re: Need more decimal places (more than 10)

[USeITWes]

I was in hurry with the post above, so I kept it brief.  I apologize for being unclear, but now I can elaborate. The member in question is using the read out from a pH probe that gives a measurement which is alway between 0 (acid) and 14 (base) which gives 7 digits of precision.  He then tried to create a script to calculate the concentration of hydrogen ions [H+].  The formula to calculate that is 10^-pH = [H+]. For a substance that is extremely basic, say a 12.6 on the pH scale, that would result in a concentration of 0.000000000000251. He attempted to use that result in another script and another equation and received a divide-by-zero exception.

I hope that clears up any confusion. Thanks for the prompt response Mr. Cherlin.  I will try your solution immediately.

------------------------
Wesley Williams
Project Assistant
USeIT Project




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(from forum)
http://forums.squeakland.org/viewtopic.php?p=9569#9569

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