ubuntu-phone team mailing list archive

[Dalius <dalius@xxxxxxxxxx>]

Automatic calculations reevaluates the whole equation when new operation is
added - therefore 1 + 2 x 4 will be 9 as it should be. Simple question: do
you have device or possibility to test current implementation? Trying live
thing might get better feeling how it works.

Another idea: we could do testing with users who have not seen previously
calculator and see how they react because we are guessing now. Preferably
we should do that with non-technical users.

Regards,
Dalius


On Mon, Mar 11, 2013 at 4:33 PM, Calum K Pringle <
calum.pringle@xxxxxxxxxxxxx> wrote:

> Hi everyone hope you’ve had a nice weekend!
>
> Last week was a bit mad because of UDS, but we have honestly been thinking
> about Calculators a lot of the time too! Dalius raised a good point about
> the ‘equals’ feature, and as it came up on the blog too, we’ve cc’d the
> list in our reply.
>
> *Why have an equals button?
> *
> We don't calculate automatically as it would muddy the order of
> operations. 1 + 2 x 4 = 9. However, calculating automatically would result
> in 1 + 2 = 3 X 4 = 12.
>
> Secondly, when two things happen at the same time on screen - displaying
> typed entry AND answer - it can be confusing.
>
> It is common to find yourself pressing the equals button for confirmation
> at the end of a calculation which also complements the physical metaphor we
> have used for the calculation history. We have also found it to be a common
> behaviour of simple calculators that pressing equals multiple times would
> repeat the previous operation.
>
> *Why do we need +/ - key
> *
> From last weeks discussion (copy below) we realised that it was not
> expected for subtract to be the entry point for making a negative number.
> For that reason, and to fit in the layout, we opted to add this button.
>
> If we follow our own direction, prioritising things like daily budgeting
> etc, minus might well be very useful! (Stay out of that overdraft!!!)
>
> Cheers,
>
> Calum
>
> -------- Original Message --------Subject:[Ubuntu-touch-coreapps]
> [Calculator] Numpad layout designDate:Sat, 9 Mar 2013 14:57:42 +0200From:
> Dalius <dalius@xxxxxxxxxx> <dalius@xxxxxxxxxx>To:
> ubuntu-touch-coreapps@xxxxxxxxxxxxxxxxxxx
>
> Hi,
>
> Here is what design team proposes for simple calculator:
> http://design.canonical.com/wp-content/uploads/numpad.png
>
> Here is our current implementation:
> http://i.imgur.com/F2DqWdL.png
>
> Design team's proposal has two unnecessary buttons:
>
> = - as I don't see any reason why calculations can't be automatic
>
> ± - it is simple calculator why we need negative numbers at all?
>
> Any other opinions?
>
> Regards,
> Dalius
>
>
>
>
> Calum Pringle
> Interaction Designer
>
> Canonical Design Team
> m: 0773 9317055
> e: calum.pringle@xxxxxxxxxxxxx
>
>