@aaribaud
Hello mate - so, there were 12 pennies in a shilling, and 20 shillings in a pound.
Half pennies were a common smaller denomination for buying every day things but there were even smaller coins, but I haven't really studied them because I looked mostly at monthly and weekly wages.
To complicate it, there were also other coins in circulation with their own values like Angels, Pistols and Guineas, but again, I'm not 100% up in their values.