A trial balance is a bookkeeping worksheet in which the balance of all ledgers are compiled into debit and credit account column totals that are equal.A company prepares a trial balance periodically, usually at the end of every reporting period. 

The general purpose of producing a trial balance is to ensure the entries in a company's bookkeeping system are mathematically correct.

Accounting equation : A (Debit) = L + 0/E (credit). 

Asset = Debit (Asset increases Debit, Asset decreases Credit)

Expenses = Debit 

Drawing = Debit

Liability = Credit 

Capital = Credit

Revenue = Credit

If the debit account is not calculated in the credit column in the above list or if the account is not omitted on any one date of the month, the amount of debit and credit account will be equal. At the same time there will be no mathematical error in the financial transactions.