Many things are confusing to somebody who doesn't know the basics. And yes, this is one of them. But you can undoubtedly find the same confusing situation with an ordinary handheld calculator, if you try.
With Mathematica, if you're unhappy with the default 6-digit display, you need only open the Preferences (aka Options, on Windows), select the Appearance tab, then the Numbers sub tab and globally change from 6 to a higher value the setting Displayed precision: Number of digits displayed in output.
You may accomplish the same thing, either globally or for a specific notebook, or even for selected cells or cell group, by using the Option Inspector: search for PrintPrecision there.
And for particular output, you may control the print precision programmatically by using the NumberForm function.
Of course that just pushes the problem further to the right of the decimal point, and you will eventually encounter the same difficulty.
On Nov 11, 2013, at 12:05 AM, Alan <firstname.lastname@example.org> wrote:
> The example below illustrates why Mathematica's display rules for approximate numbers are very confusing for students. Should this be considered a user-interface bug? If not, why not? In any case, can the default display be changed to something more familiar from spreadsheets and other computing languages? > Thanks, > Alan Isaac > > In:= tv = TimeValue[1, 0.04, 3] > tv == 1.124864 > tv == 1.12486 > > Out= 1.12486 > > Out= True > > Out= False >
--- Murray Eisenberg email@example.com Mathematics & Statistics Dept. Lederle Graduate Research Tower University of Massachusetts 710 North Pleasant Street Amherst, MA 01003-9305