Convert between decimal and hexadecimal, or do arithmetic directly on hex values.
Hexadecimal is base 16, which needs 16 distinct digit symbols. After 0-9, it continues with A-F to represent the values 10 through 15 in a single digit.
0x is the standard notation marking a number as hexadecimal (used widely in programming) so it isn't mistaken for a decimal value — 0x1F means 1F in hex, not 1F in decimal.
It parses both hex values as base-16 numbers, converts them to decimal, applies the chosen operation (+, −, ×), then converts the answer back to hex — the decimal equivalent is shown too.