octal , hexa question

[cowboy55]

I read the following post from Steve about calculating octal and hexa from binary
"first convert any int to binary
then if it is hex you need then every four binary digits summed
represent one hex digit
Ex.
int 28 bin 11100
for hex break bin into quads 0001 : 1100 this gives 0x001C
for oct break bin into trips 011 : 100 this gives 034"

Can anyone explain this method in more detail??
thanks