The other thing you can take from accountancy is double- entry... A toy example. Money was spent on x, so it gets charged to x account and removed from the b

The other thing you can take from accountancy is double- entry... A toy example. Money was spent on x, so it gets charged to x account and removed from the bank. More correctly debit x-expense, credit bank. Credits are by convention negative numbers. Now no matter what happens your accounts always need to balance, ie the entire set of ledgers add up to zero. Audit checks are now trivial, if either your balances table or your transactions table do not sum to zero, alert somebody. It has been working for accountants for 2000 years! https://en.m.wikipedia.org/wiki/Double-entry_bookkeeping_system https://en.m.wikipedia.org/wiki/Double-entry_bookkeeping_sys...