[Linux-aus] Re: High school computing texts

[Jon 'maddog' Hall]

On Thu, 2007-03-22 at 11:43 +1030, David Drury wrote:
> Paul Shirren writes: 
> 
> > In South Australia in the 1970s, Mr Ward taught my year 3/4 primary class 
> > to count and add in trinary and convert back and forth to decimal. We also 
> > learnt about sets, intersections and unions. I think it was called "new 
> > maths" and was frowned upon by people at the time.
>  
> 
> Sorry I have to post the obliatory song from Tom Lehrer here
> 
> Three from two is nine, carry the one, and if you're under 35 or went to a 
> private school, you say seven from three is six, but if you're over 35 and 
> went to a public school, you say eight from four is six ...and carry the 
> one, so we have 169.

I assume he was subtracting in the base 10.

We were taught that you could not subtract three from two, that you
first had to "borrow a 10", then proceed, so it became 12-3 giving you
nine.  Then you were left with "3" in the next column from which you
were subtracting seven, but you can't do that either so you have to
borrow a group of ten from the left again, leaving you with 13-6 or
seven for that column.  Then we had two in the most significant column
that we subtracted one from to get the answer.  Each column to the left
was simply the base amount of the column you were in.

This worked the same for every base, whether you were over 35 or not,
went to public school or private school.

Maybe if I was good at singing I would screw it up, but I haven't tried
doing math to song.  That to me would sound too much like Chisenbop.

md