"Tim Streater" wrote in message
.. .
Everyone should be able to do mental arithmetic, and even more
importantly, be able to quickly work out an approximate answer to a
calculation, which will tell you whether your final calculation is
*reasonable*.

I wish I'd been taught how to do *mental* arithmetic and how to process the
carry/borrow digits and to retain a mental running total. I never was: I was
taught how to do it on paper, with rules for carrying/borrowing digits which
I can do fine (albeit slowly and laboriously).

My wife worked in a bakery as a summer job during school, so she quickly
became adept at adding up prices of five doughnuts at 13p each, two loaves
of bread at 27p each, 7 seven flapjacks at 17p each, *without having to
write it down and add up on paper*. I marvel at that skill.

I'm OK at estimating an approximate value - or at least knowing when a
calculator answer is clearly ridiculous due to mis-keying.

I'm not one of those people who needs a calculator to perform simple
calculations like adding 2 and 3 or multiplying by 10, and I am lightning
fast with lookup-table things like times tables up to 12, but for anything
else I do at least need a pencil and paper to act as a visible short-term
memory to handle the running total and carry digits.


At my school, one of the teachers had a bizarre punishment for minor
offences - like being caught cheating in weekly tests: "Tarthur's Cubes".
He'd decide that an offence merited a three-digit cube or, if it was more
serious, a four- or five-digit cube. He'd get members of the class to call
out the required number of digits to make up the number. For the next
lesson, the culprit then had to perform long multiplication, showing all the
carry digits, and then multiply that answer by itself to end up with
(number)^3. Then you had to perform long-division (showing all the working)
and divide that answer by itself. You know that you should end up with the
number you started with, but the punishment was that it was so slow and
laborious and tedious that you would think twice about committing the
offence that was being punished.

The prefects had similar slow-and-laborious punishments:

- Minor things merited "columns of The Times", for which you were given a
page of yesterday's newspaper and you had to go through the required number
of columns of newsprint, inking-in every letter with a "counter" (an
enclosed space, such as in "a", "b", "d", "e" etc), with a standard rate of
so many column-inches of the following day's paper for every letter that you
missed.

- More serious offences rated "an impo" (imposition) which involved writing
lines ("I must not lie to a prefect") on special "impo paper" which had red
and green lines ruled on it at about 5 mm spacing. The body of the letters
had to fit exactly within the green lines; the ascenders (of "b", "d", "l")
had to rise to the upper red line and the descenders (of "p", "q", "y") had
to go down to the lower red line: this involved writing more slowly and
laboriously than normal handwriting. It was the job of the master-on-duty
each day to make himself available during lunch break to hand out pages of
"impo paper" and to check this against notes that the prefects had given him
("Smith has been given an impo of 50 lines").

Corporal punishment was allowed (this was the 1970s) but could only be
administered by masters, not prefects, and was more often threatened than
actually performed. One master who taught us English but also taught sport
would produce "Mini Whacker" (a size 5 trainer shoe), "Tiger Whacker" (a
size 7 with go-faster stripes) and "Super Whacker" (a size 10 on which he
would draw an "S" in chalk and keep hitting you until all the chalk had
transferred itself from shoe to backside. I never saw him *use* these, but
he often *threatened* to.

I was only actually "tanned" once, and that was for what we euphemistically
called "master-baiting" (!) - imitating and taunting teachers. I did a very
good impression of the Nelly, the biology teacher, as we were getting
changed from swimming and he walked through the changing room from the
biology lab. You could see him debating with himself whether to let it go or
to make a big issue of it, and he decided that he had officially heard what
I'd said. "Brrrrrrinnnngg meeee a slippppperrrrrrrrrr", he yelled.
"Bennnnnnn Doverrrrrrrrr". And he got hold of my hair at the front and
pushed my head down (making my bum stick out) as he raised his arm to get a
good swing, then he yanked my head up as he brought his arm down on my bum
which retreated from his arm - his actions, always rather robot-like, were
180 degrees out of phase! Every time he brought his arm up for another
swing, he bashed his knuckles on the locker doors - I could hear him
muttering and cursing "Ouch, ****" each time he did it. I had to make all
the right sounds of pain, though the only pain I was in was through trying
to stop myself bursting out laughing at how ludicrous it must have looked to
be tanned by "a robot". I learned later from my mates that Nelly was beside
himself with fury and they feared for my safety at one point and were about
to intervene because he looked as if he was going too far. I saw him years
later and recounted the incident, which he still remembered, and he said the
deciding factor in him deciding not to ignore it was that I'd used his
surname: in a mechanical voice, I'd said "Eek! Look. There goes Nelly
[surname]. I wonder if he's going to feed his crock-oh-dile (*)", but if I'd
omitted his name, he'd have ignored it. Grrr.


(*) It was reputed that he kept a pet crocodile in the school pond and fed
it on first-years. The word was always said with very exaggerated stress on
all three syllables - crock-oh-dile.