The keyup object sends the ASCII of the key which is pressed and then released, to its outlet.
The ASCII of ‘0’ is 48, ‘1’ is 49, and so on.
First press Reset to clear float. Then press 3 numbers, such as 7, 9, 2. They will be properly routed by the demux and incrementing index to the 3 number boxes. Any further input will not be recorded, unless Reset is pressed again.