I was playing FSX again lately and was flying the B737-400. So I hope it is simulated correctly and this question isn't dead on arrival :-)
It always bugged me, that the altitude display on the MFD is very ambiguous when you are immediately below a "round" value:
On first glance everyone (ok..me) would read the altitude to be 9900 ft. Only if you know what to look for and spot that the numbers carry on downwards you can deduce that you are actually at 10000. The reason is that the second significant digit does not roll over smoothly but ticks over appruptly when the next round value is surpassed.
Granted, 100 ft may not be a huge difference, but it seems very unneccessary to have it like that. If the first two significant digits behaved more smoothly without this round-down like behavior I would recon that it would be way less ambiguous.
Why is the altitude display designed that way?