On: Show HN: Kalk, A calculator with math syntax, comp...

[dmitriid]

For fun, try to run this: `2 + 2 * 10%` in all calculators you have access to: on you phone, on your desktop, in kalk.

As they say, "the answer will surprise you" :)

[a1369209993 → dmitriid]

  $ units
  You have: 2 + 2 * 10%
    Definition: 2.2

ITYM "the answer may surprise you", and in this case it did not.

[dmitriid → a1369209993]

I did say "in all calculators you have access too, including kalk" ;)

https://news.ycombinator.com/item?id=27336530

[npongratz → dmitriid]

Performing the calculation with Soulver did not surprise me (being what I calculated in my head ahead of time):

    2 + 2 × 10% = 2.2

At the risk of admitting my ignorance, yet more interested in learning something new: should this answer (2.2) surprise me?

[dmitriid → npongratz]

Wolfram Alpha and iOS also give 2.2

On MacOS the answer is 2.4

In kalk it's 2.002

On Windows it's 0.4 in simple calc, and 2 in programmer calc (and there's no % in engineering calc)

[app4soft → dmitriid]

2.2 via Google[0]

> and there's no % in engineering calc

Use 0.1 instead of 10%, it has the same vibe ;)

[0] https://www.google.com/search?gbv=1&q=2%2B2%C3%9710%25&oq=&a...

[sp1rit → dmitriid]

What about the win32 calculator shipped with w7 and w10 ltsc?

[paddim8 → dmitriid]

Haha damn, didn't expect that

[TchoBeer → dmitriid]

Android gives me 2.2

[kzrdude → dmitriid]

Is there an explanation for the answer in kalk? Seems buggy

It seems like an expression like "1 * 10%" in kalk is computed as if it means "1% * 10%" => "0.01 * 0.1" => "0.001"

[j1elo → dmitriid]

The calculator that comes with MIUI 12 (Xiaomi phone) writes everything as you type, like you'd expect.

But, the moment you type `%`, it instead replaces `10` with `0.1`. So in the end the screen shows: 2+2x0.1 = 2.2

I guess not as surprising as you expected :-]

[dmitriid → j1elo]

I did say "in all calculators you have access too, including kalk" ;)

https://news.ycombinator.com/item?id=27336530

[anthk → dmitriid]

Forth, once using fixed point and scaling 2e+2:

      2 dup 100 10 */ swap 100 * + .S 220 OK