PTB + GUI in Matlab (R2018a) - Arithmetic Tasks

Hi everyone, 


I would like to use Psychtoolbox for memory arithmetic tasks. I would like to show several numbers one by one on a screen ; after numbers presentation the subject need for example to make an addition of all seen numbers using a GUI dialog box. I would like that the subject see its answer in the screen to be sure he/she is in accordance with it. I am a new in PTB. Therefore, I had the idea to use the GUI of Matlab and combine it with PTB. It seems to be not a good idea, it doesn't work well. 


I have found some functions like Ask or TwoStateQuery from PTB . However, these functions communicate with Matlab command and I prefer that the subject do not interact directly with the window command of Matlab. 


Do you have any idea/suggestion how I can implement my arithmetic task? 


NB: I would like to use Psychtoolbox because I use several other tasks as Stroop and Auditory Tone Discrimination already implemented in this software. 


Many thanks in advance, 

Eva