conversion table

inner green box shown the convertion between hexadecimal and binary
inner yellow box shown the conversion between octal and binary..

noted:

use a group of 3 bit (start from LSB to MSB) for octal to binary and binary to octal...

while use a group of 4 bit (start from LSB to MSB) for hexadecimal to binary and binary to hexadecimal

LSB= least significant bit ( the number of bit at most right hand side)
MSB= most significant bit ( the number of bit at most left hand side )