ubuntu-phone team mailing list archive

[Calum K Pringle <calum.pringle@xxxxxxxxxxxxx>]

Replies in line

On 11 Mar 2013, at 18:33, Dalius wrote:

> 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.

Wouldn't that be more confusing though, as then you'd *think* you were multiplying 3 by 4, not 2, because it would be a 3 that you see on the screen?

> 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.

Sure, I'll let you know. However most users will have seen a basic calculator in physical form! ;-)

Thanks Dalius, this has made such great progress! 

> 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 design
> Date:	Sat, 9 Mar 2013 14:57:42 +0200
> From:	Dalius <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
> 
>