This demo appears to date from 2012: https://plus.google.com/+NiklasvonHertzen/posts/Qo6T85W8sFQ
Be sure to read how it works: https://plus.google.com/+NiklasvonHertzen/posts/Qo6T85W8sFQ
Very smart and creative solution.
Pressed 1, 5, 6
Got 142
Interesting idea, but might need more work.
If I type 55555 everything disappears
Found myself reminded of a Chaos Computer Congress presentation.
It is fun to see how the calculator is off when you scale the page in your browser (ctrl+scroll). 5*5=24!