Showing calculation details on custom record field
I have a custom record that gives us a list of laptops owned by the organization and the respective owners with other details. The current requirement is to add a field called ‘Current Value’, which will show the value of the laptop after deducting 20% per annum after the date of purchase. This part is fairly straight forward but what I am struggling to configure is the place where it will show the calculation in detail. For example, if a laptop worth £1000 is over a year old, the current value shows £800 but I need to show somewhere on the record that the current value is derived by reducing 20% from the original value. I was thinking of getting a sublist but was just wondering if there is a better way to achieve this.