24 Oct
2011
24 Oct
'11
10:42 a.m.
On Mon, 24 Oct 2011, Chuck Guzis wrote:
I call it "exponential" notation.
"Scientific" notation is also
fairly descriptive. FORTRAN's "real" is a convenient, if not
accurate, shorthand.
convenient? YES.
"not accurate"?? That is a GROSS understatement. It seriously interferes
with beginning students understanding variable types. In addition to
causing them to choose it inappropriately in order to avoid the "ERRORS!"
of integer division, it causes some of them to get seriously hung up on
"ERRORS!" when they finally discover that it is an approximation.
On "integer"s, it is a STRUGGLE to get them to "revert" to
"quotient"/"remainder" ("15/4 IS NOT 4.75! It is 4, REMAINDER
3").
"It was so difficult to learn "decimals"; now we need to UNLEARN it
all!"
On "REAL"s, it is a STRUGGLE to get them to understand that it is NOT an
"ERRORS!" when an approximation is not exact. One exercise that helps a
little is to make them divide 1 by 3; write down the result; TURN OFF the
calculator; multiply whatever they wrote down by 3; and then EXPLAIN the
"ERRORS!".