I think people use the decimal system because we have 10 fingers and it's more intuitive that way.
Computers use octal or hex because the base is a power of 2 (8=2^3, 16=2^4), and the computers work in binary, 0 or 1, 2 values.
In hexadecimal, that would be 0x2E, which is equivalent to 46 in decimal, which in binary is 101110.
10,923 decimal 2AAB Hexadecimal 25,253 Octadecimal
111111 in binary is 255 in decimal which is FF in hexadecimal (i.e. 15 units and 15 16s)
Octal and hexadecimal numbers are useful for humans as they compactly represent binary numbers:each octal digit represents exactly 3 binary digitseach hexadecimal number represents exactly 4 binary digitsFor example, instead of trying to read (and remember) the binary number 100111001001 it can be represented as hexadecimal 0x09c9 or octal 04711 which are easier to read (and remember) for humans.
100000000. It's decimal equivalent is 256.
Decimal is base 10. Binary is base 2. Octal is base 8. Hexadecimal is base 16.
10011101: Decimal = 157 Hexadecimal = 9D
4F7B: Binary = 100111101111011 Decimal = 20347
The decimal, binary, hexadecimal, and roman numeral systems are fairly well known.
It is used because it is easier to convert to and from binary to hexadecimal than decimal, and it uses less characters than binary. For instance: decimal: 65535 hex: FFFF binary: 1111111111111111
If the above is decimal then in hexadecimal it is 2964492C2. If it is binary then in hexadecimal it is 7DA. If it is octal then in hexadecimal it is 49241208.
Decimal: 170Hex: AA
In hexadecimal, that would be 0x2E, which is equivalent to 46 in decimal, which in binary is 101110.
Any data is stored internally in the computer as binary digits, but those are "bulky" - you need 4 binary digits for every hexadecimal digit, so hexadecimal is really a kind of shortcut to write out binary numbers.Decimal is another option, but conversion between binary and decimal is more cumbersome than with hexadecimal. Therefore, for the new IP addresses (IP version 6), they decided to write them down in hexadecimal, instead of the decimal that is used for IPv4.
1
221122: Binary = 1000100001000100100010 Octal = 10410442 Decimal = 2232610
10,923 decimal 2AAB Hexadecimal 25,253 Octadecimal