In this lesson, students continue their study of accounts in their ninth year, focusing on the concept of the “books of original entry.” This includes understanding how transactions are initially recorded in a cashbook or payment entry before moving to accounts in the ledger through the double-entry system. The lesson covers cash and credit sales, demonstrating how to issue receipts or invoices and record them appropriately. Additionally, students learn about managing transactions related to goods purchased on credit and how to handle returns effectively.