Help ,Please,afr gauge Newbie to Arduino

It's still a mess as there are two codes inside each other. But OK

Not soving your problem but things like x1 = x1 ++; are not advisable; just x1++; should do the trick.

There is hardly ever a use for goto; and this code is definitely not one where goto is needed.

To calculate hundreds, you can simply divide by 100

x1 = value / 100;

Next you can subtract x * 100 from value and repeat the process for the dozens; x2 = value / 10;