So when they start to do division, how do they cope with say 20 divided by
3?
Phil Hall
----- Original Message -----
From: "Bill Hooper" <[EMAIL PROTECTED]>
To: "U.S. Metric Association" <[email protected]>
Sent: Monday, October 10, 2005 10:19 PM
Subject: [USMA:34786] Re: fractions
On 2005 Oct 10 , at 3:19 PM, Philip S Hall wrote:
How would you explain to your pupils the meaning of numbers like 0.2,
4.5, 2.342 etc
Remember you have to do with this without resorting to common
fractions.
How would I explain decimal fractions without reference to common
fractions?
Easy:
I would explain it just as I would explain the meaning of the digit "2"
in the number "23". The two counts how many tens there are, where tens
are groups of things when they are grouped in equal bundles of ten
items each.
Going the other way, if the number was "2.3", the digit "3" tells how
many tenths there are, where a tenth is one part when the whole is
divided into ten equal pieces.
Yes, the concept of one-tenth is required but it does not need to be
written as "1/10" and it does not need to be related to other
non-decimal fractions like 1/3 or 1/12 or 17/32, etc. (And the parts do
not even need to be named "tenths", if your really want to avoid even
the appearance of using common fractions. You could call the parts
"pieces of ten", or "parts", or "zippies", or "elephants" and get the
same satisfactory result.)
Explaining that one whole may be divided into ten (equal) parts is no
more difficult than explaining that numbers of wholes may be grouped
into (equal) bundles of ten wholes. (And, explaining that hundredths
are just tenths divided into ten parts is no more difficult than
explaining that hundreds are just tens grouped into bundles of ten
tens, etc.)
Regards,
Bill Hooper
Fernandina Beach, Florida, USA
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