A more thorough explanation:

Definition: Scalam (skay-ləm) is a Latin term that means "scale." In history, it was used to refer to a method of paying money to the Exchequer, where an additional sixpence was added to every 20 shillings to make up for a deficiency in weight, even though no scales were used.

During the medieval period, people paid taxes to the Exchequer using the scalam method. For instance, if someone owed 20 shillings, they would have to pay an additional sixpence, which was equivalent to 2.5% of the total amount. This extra amount was added to compensate for any weight discrepancies that might have occurred during the transaction.

Another example of scalam is when merchants used it to measure goods that they sold. They would use scales to weigh the goods and ensure that they were selling the correct amount. However, scalam was different because it did not involve the use of scales, but rather an additional fee to make up for any weight discrepancies.

These examples illustrate how scalam was used in history to ensure that transactions were fair and accurate, even though scales were not always used. It was a way to compensate for any discrepancies that might have occurred during the transaction, and it helped to maintain trust between buyers and sellers.