Without rounding, 1/3 becomes 0.3333333333333 and 1/7 becomes 0.142857142.
What's wrong with 0.33 or 33% or 0.14? Accurate enough for most people's
needs.
I don't think we're on the same wavelength here or maybe we're at cross
purposes.
I'm perfectly happy with the idea that decimal form is better for
measurment. With decimal we can round measurements or express them to any
degree of accuracy we like with an appropriate choice for the number of
significat digits and the last digt for rounding. That reflects the nature
of measurement itself. All measurements are an approximation to varying
degrees. Decimal notation lends itself to that perfectly.
What concerns me is the suggestion that somehow fractions (of the form x/y)
can be surgically removed from the mathematics curriculum. I don't
understand how you can talk about tenths and hundredths etc, in isolation
from the general concept of an nth of something! For example 0.237 is just
code for 237/1000 They are closely related and inseparable.
Now I realise that some of you are merely saying that it is a waste of time
learning to do arithmetic with x/y type fractions because nobody uses them
in practice, except maybe to cope with measurement units where you end up
with awkward fractions.
Well I think there is more to it than that. Even without non-decimal
measurement systems it would still be quite important for kids to learn the
principles. But in order to teach it you need a means of assessment. That
can only be done by exercises that will inevitably involve a certain amount
of doing arithmetic.
There is also the point that time isn't decimal nor is angular measurement
in degrees.
It's all too easy for the likes of us as adults who take for granted what we
know about fractions and are able to instincitively apply them to the idea
of a half or a quarter or a two thirds of something. We are able to do this
because we have benefitted from a rounded education in basic mathematics. We
musn't try to deprive future generations of this. It's not part of the deal
where metrication is concerned.
Phil Hall
