Have fun calculating with Freehand Calculation.
Write your operations by sliding your fingers on the board and you will get the answer !!!
in aia file you 'll find how
Use parameters to set dimension of canvas ,
set line width
set backgroundcolor
set possibility to get action
For those interested in the aia file contact me via PM
https://drive.google.com/file/d/1v2lCyddX5VeP5RpsdCNER_0LlCDuKMo_/view?usp=sharing