The term "slash notation" refers to the way a processor reads an IP address. The "Watchguard" website gives a table showing the most common network masks and their equivalent in slash notation.
period
period
240.185.8.103
12
dotted decimal notation
Octets
Dotted decimal notation
Dotted-decimal notation
255.255.248.0
addresses are 32-bit numbers often expressed as 4 octets in "dotted decimal" notation (for ... Internet Corporation for Assigned Names and Numbers ...
Dotted Decimal
Dotted decimal