Re: TI-92, HELP! Significative numbers!!!
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Re: TI-92, HELP! Significative numbers!!!
>Apart from that, he was talking about significant digits. Very simple
>thing, just set FIX 2 as said before, then choose:
>Exponential Format = Scientific
>
>Like this,
>17000 --> 1.70E4
>123.45 --> 1.23E2
>1.7 --> 1.70E0
>0.001 --> 1.00E-3
>
>and so forth. You always get 3 significant digits.
You have also demonstrated a lack of knowledge as to what significant digits
really means. Number of decimal places IS NOT the same thing as significant
digits. For instance, using your own examples:
17000 has two sig figs ----> 1.7e4
123.45 has five sig figs ---> 1.2345e2
1.7 has two sig figs ---> 1.7e0
0.001 has one sig fig ---> 1.e-3
The thing none of you quite realise is that the rounding for sig figs must be
determined on a case by case basis. You can't just say, "I will want three
sig figs for all my calculations." No. It doesn't work that way. You
must look at the number of sig figs in the numbers you are calculating, and
from that determine the number of sig figs that the answer needs to be
rounded to. That is why the human operator must to this by himself. The
TI-92 is not programed to do sig figs, and such a thing would be very hard
to program, while it's not so hard to just do it by yourself, as long as
you actually know how.
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