[R-390] The Mathematics of Teledyne Identification

[Thomas W Leiper]

On Mon, 10 Jun 2002 10:58:03 -0500 blw <ba.williams@charter.net> writes:
> 
> > I think the math works out something like
> > 
> > R-390A + R-390A x R-392 = R-390.

That is incorrect...

R-390A + R-390A x R-392 = [R-390A]R + [R-390A]R -392

= [R(2) - 390AR] + [R(2) - 390AR] - 392

= 2R(2) - 780AR - 392


You can't take three from two, two is less than three...
So you look at the four in the tens place...
Now that's really four tens, so you make it three tens...
Regroup, and you change the ten to ten ones and you add
it to the two and get twelve and you take away three..that's nine.

Hooray for New Math, New who who Math...
It won't do you a bit of good to learn...New Math
It's so simple, so very simple...
That only a child can do it!