C++ programming

Chapter 6 has been difficult for me to understand so any help is appreciated.

For many years the British Empire used a three-unit monetary system based on pounds, shillings, and pence. 12 pence 1 shilling and 20 shillings 1 pound. Amounts in this system are printed out in a two-decimal point notation: E6.3.s (meaning 6 pounds, 3 shillings, and 5 pence),. This is just enough detail (data and functions) to make British currency an interesting demonstration of structures and functions