Binary to Hex

What is the simplist way to convert a number from binary to hex and back the otherway,

I can convert both to decimal, its for an upcoming exam I have (ps I'm allowed a calculator)

Manually it is easiest to convert directly from one to the other - because 4 bits maps directly to 1 hex digit.

1111 = F (or 15 decimal)
0010 = 2 (or 2 decimal)
1010 = 9 (or 9 decimal)

so:
1111 0010 1010 = F29 (no idea of the decimal!)



Some scientific calculators can convert for you.

bin to hex
break the binary into groups of four starting at the right

11010100101011

= 0011 0101 0010 1011

each one of those 4 groups represents a hex digit; you can work right to left or left to right and I added the leading zeros to the front just to keep the groups of 4 vibe

1011 = B
0010 = 2
0101 = 5
0011 = 3

= 352B

hex to bin
kinda the same thing as each of the hex digits needs to become a 4 character bin:

B = 1011
9 = 1001
6 = 0110 <--remember the leading zero
1 = 0001

so

4C901 is going to be 5 groups of 4 binaries

4 C 9 0 1
0100 1100 1001 0000 0001

I'm taking the same kinda class so good review for me too.