Adding a Number class to encapsulate a bit more information
Making it lazy
Modifications to Account to include the original OCR numbers
Hooray for default values
Logic that actually works

This goes through and provides me with a list of possiblities for one
off other numbers. like 0 could be 8, and 1 could be 7.
Implement the 4th use case

This goes through the account numbers and tries to find valid accounts
that might be off by one tiny bit.