This calculator by default gives you a Hexadecimal keyboard so you can do Hex arithmetic (add, subtract, multiply, and integer divide, and modulus)
Notice that integer division is different than normal division, in that the answer is only the whole portion of the result. There is no remainder, decimal, or fractional component. The modulus operation is made available so any remainders can be calculated if needed.
The "Mode" button cycles from Hexadecimal to Decimal, Octal, and Binary then back to Hexadecimal, modifying the keyboard as needed.