Farthings
In days gone by I worked for a large life assurance company who had a reverse-lira issue. Some of their 'Industrial Branch' old policies (life assurance collected weekly by agent knocking on doors) went back decades, and when they matured they need to be processed on modern computer systems - which had to handle weekly premiums of 1/5d or even some in farthings. So they multiplied the pounds by 960 and did all their sums in farthings.