Please share as bur.sk/2022/scitanie/en.html, because the links to the individual pages might change in the future; also the problem pages do not contain a link back.
The page only works on a computer, doesn't work on a phone; sorry for that.
The following links will guide you from the easiest to the most difficult exercises in integer addition and subtraction. The problems are randomly selected, the next time you visit the problem page they will be different. The page does not remember which exercises you already did.
Correct solutions are automatically highlighted in green, incorrect ones in red. To move to the next problem, click "Tab" or use the mouse.