Without wanting to sound overly blunt, I sincerely hope you're joking
If you know the system is random, then you wont make the mistake of assuming you know your current position in the sequence. Having to enter the units of measurement is the the backup.
The reason why so many errors happen is because they can't help but assume they know where they are in the data entry sequence. If you take away the ability to make that assumption then you solve the problem.