Here's a simple one.
Write a function or program when given a number in base 10 as input, it will return or print that number's value in Hexadecimal.
15 -> F 1000 -> 3E8 256 -> 100
- No built-in Hexadecimal functions whatsoever
- Letters may be lowercase or uppercase
- You will only need to worry about non-negative integers, no negatives or pesky decimals
- It should work with any arbitrarily large number up to language's default type's limit.
- Newline not mandatory
- As usual, this is code-golf, so shortest code measured in bytes wins!