See Poole on "Matthew 18:35" The Roman penny is the eighth part of an ounce, which after five shillings the ounce is seven pence half penny. (Matthew 20:2).
Related Commentaries of Matthew 18:28
Matthew 18:28
28 But the same servant went out, and found one of his fellowservants, which owed him an hundred pence:c and he laid hands on him, and took him by the throat, saying, Pay me that thou owest.