Comments on: Gnome calculator is broken (on Fedora)

By: Chris Stevenson

Chris Stevenson — Wed, 02 Feb 2005 04:24:30 +0000

Um - beg to differ.

Mathematics has well established rules of precedence and has had since the 1600s (see the link in the blog entry). This is why I can write an equation like ax + by = 2 and don’t have to specify (ax) + (by) = 2

Programming languages are the ones that are inconsistent.

When I learned it in primary school, we called it BODMAS - and it is indeed the universal set of rules for maths - try Googling for it.

FYI: My degree is in Physics and Mathematics :-)

By: Jordan

Jordan — Wed, 02 Feb 2005 02:06:54 +0000

First of all, its not wrong. There are no parenthesis in that statement, therefore according to simple mathematics (NOT programming mathematics), all calculations are taken in turn. 2*2 = 4 + 2 = 6 * 2 = 12

Now, 99% of programming languages will do any multiplaction or division first (after evaluating any parentheticals), but really, the Gnome calculator is simply enforcing stricter rules (requiring the 2*2 to be in parenthesis).

Most programming languages actually hijack mathematic principles to correct for programmers not being mathematicians.

By: Robert Watkins

Robert Watkins — Tue, 01 Feb 2005 21:58:53 +0000

Oh, and the answer is 12 in the Windows XP calculator in the ’standard’ mode, and 8 in the ’scientific’ mode. Just like you’d expect. :)

By: Robert Watkins

Robert Watkins — Tue, 01 Feb 2005 19:20:09 +0000

They’re emulating a classic mechanical calculator. :) Stack-based calculators are a purely electronic invention; mechanical calculators had to determine the answer at each step.

Essentially, most calculators automatically evaluate the expression as it stands right now, saving you the trouble of hitting equals. For most “kitchen arithmetic” problems, this is the desired behaviour.

It’s the job of the human to enter the values into the calculator in the order of desired evaluation. :) Try it with a $10 pocket calculator for comparison. Oh, and a calculator isn’t a spreadsheet.

The scary question is… why did you need a calculator to work out 2*2+2*2? :)