Similarly, an old accountant's trick: If something doesn't balance, try
dividing the error by three. If it IS divisible by three, it's probably a
couple transposed digits.

        For example:

12345 - 12435 = -90, which is divisible by three.

        Also, to tell if a number is divisible by three, add the digits. If the
sum is divisible by three, so is the original number.

Harold


On Thu, 7 Jun 2001 16:54:01 -0400 Thomas McGahee
<tom_mcgahee@SIGMAIS.COM> writes:
> I'm too busy now to tackle the problem (end of school,
> and as a teacher I am inundated with work!), but
> I offer this observation: The sum of the digits of any
> multiple of nine will always add up to nine. If you get
> a multi-digit answer, then add those digits as well.
>
> For example, the digits in 2736 add up to 18. The digits
> in 18 add up to 9, so 2736 is an integer multiple of 9.
>
> Fr. Tom Mcgahee
>
> ----- Original Message -----
> From: Scott Dattalo <scott@DATTALO.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Thursday, June 07, 2001 3:55 PM
> Subject: [pic]: 9
>
>
> > Let's turn all of this amateur mathematical rambling about
> repeating 9's
> into
> > something useful:
> >
> >  What's the most efficient PIC code (execution time) to determine
> if a
> number is
> > evenly divisible by 9?
> >
> > I think it can be done in 12 instructions, right Dmitry.
> >
> > Scott
> >
> > --
> > http://www.piclist.com hint: The list server can filter out
> subtopics
> > (like ads or off topics) for you. See
> http://www.piclist.com/#topics
> >
> >
>
> --
> http://www.piclist.com hint: The list server can filter out
> subtopics
> (like ads or off topics) for you. See http://www.piclist.com/#topics
>
>

FCC Rules Online at http://hallikainen.com/FccRules
Lighting control for theatre and television at http://www.dovesystems.com

________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno.com/get/tagj.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.