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===Hexadecimal Numbers===

''For folks who don't know what a hexadecimal number is...'' Okay, decimal numbers go like this: 0 1 2 3 4 5 6 7 8 9 10 11..., while hexadecimal numbers go like this: 0 1 2 3 4 5 6 7 8 9 A B C D E F 10 11 .. 19 1A 1B ... etc. Hex 'A' equals decimal 10, hex 'B' equals decimal 11, ... hex 'F' equals decimal 15. Since hexadecimal is base 16 ('hex' = six ~~+~~ 'deci' = ten), they "roll over" at 'F' (= 15 decimal), the same way that decimal numbers roll over at 9.

To convert a two digit hex number into decimal simply multiply the first digit by 16 and then add it to the second digit. E.g '42' in hex is 4*16 ~~+~~ 2*1 = 66. Or 'FF' in hex is 15*16 ~~+~~ 15 = 255.

Hex numbers are useful in computers because they map very directly to the way computers actually store numbers (in binary). Two hex digits is the same thing as a byte which is the same thing as 8 bits.