Conversion Octal to Hexa

Question

How is made the conversion to Hexadecimal by Octal?

I know there is a method that is converting to binary and after to octal. There's another?

How it works? What is the name of this conversion procedure?

Answer 1

Replace each octal digit with a string of three bits (with leading zeroes if necessary) representing its binary value. Then regroup them in groups of four, starting from the right, and write the hex value of each such group. Let's take a simple example: $1234567_8=\underbrace{001}_1\ \underbrace{010}_2\ \underbrace{011}_3\ \underbrace{100}_4\ \underbrace{101}_5\ \underbrace{110}_6\ \underbrace{111}_7=$ $=\underbrace{0}_0\ \underbrace{0101}_5\ \underbrace{0011}_3\ \underbrace{1001}_9\ \underbrace{0111}_7\ \underbrace{0111}_7=053977_{16}=53977_{16}$. Why strings of three and four bits ? $\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\qquad\quad$ Because $8=2^3$ and $16=2^4$.