This is the latest version of my calculator, it can make additions between two digits numbers and give the result for a max of 198 (99+99) on the LED displays
You can see on my YT Channel the entire process of creation from the first prototype to this.
The LED display technology isn't a creation of mine, it was developed by Starmapking, credits to him.
Substrate link in description
https://youtu.be/f_hBG3gnn-A