Convert octal to hex, w/out converting to Binary


by dk702
Tags: binary, convert, converting, octal, w or out
dk702
dk702 is offline
#1
Aug25-04, 08:11 PM
P: 6
I have been trying to convert a from octal to hex and hex to octal without using binary. I believe the method is called repeated divison.

Example of problem I am trying to solve,

Convert 173 octal(123 dec) to hex


173 oct / 16 oct = 10 oct remainder 13 oct

10 oct / 16 oct = 0 oct remainder 10 oct


Reading up (1st division remainder is less sig. digit, and last is most sig.)


answer 1013 hex = 4115 dec. WRONG

answer should be 7B Hex
Phys.Org News Partner Science news on Phys.org
Cougars' diverse diet helped them survive the Pleistocene mass extinction
Cyber risks can cause disruption on scale of 2008 crisis, study says
Mantis shrimp stronger than airplanes
ehild
ehild is offline
#2
Aug26-04, 09:06 AM
HW Helper
Thanks
P: 9,834
Quote Quote by dk702
I have been trying to convert a from octal to hex and hex to octal without using binary. I believe the method is called repeated divison.

Example of problem I am trying to solve,

Convert 173 octal(123 dec) to hex


173 oct / 16 oct = 10 oct remainder 13 oct


answer should be 7B Hex
You can not mix octal and decimal numbers, and that "16" was decimal. Apply the repeated division on the decimal form of octal 173:

123=7*16 +11 which is 7B in hexadecimal form.

The conversion is possible also without using decimal form.
Working in the "hexadecimal word" 8=10/2

173 (oct) = 3+7*8+1*8*8 =3+7*10/2+1*10/2*10/2=
=3+(6*10/2+10/2) + 10/2*8=
=3+(3*10+8)+(4*10)=(3+4)*10+(3+8)=7*10 + B = 7B

(It is similar backwards. You know that the base of the hexadecimal numbers is 20 in your octal system. If you have 173(hex), for example, it is
3+7*20+1*20^2=3+(7*2)*10+4*100=
3+(10+6)*10+4*100=3+6*10+5*100=563.)

ehild
chronon
chronon is offline
#3
Aug26-04, 09:47 AM
chronon's Avatar
P: 499
Quote Quote by dk702
173 oct / 16 oct = 10 oct remainder 13 oct

10 oct / 16 oct = 0 oct remainder 10 oct

Reading up (1st division remainder is less sig. digit, and last is most sig.)
answer 1013 hex = 4115 dec. WRONG

answer should be 7B Hex
You can get this to work if you 1) Use the correct representation of the hexadecimal base (20 oct) and 2) Interpret remainders as single hexadecimal digits (which they must be).

173 oct / 20 oct = 7 oct remainder 13 oct (B hex)

7 oct / 20 oct = 0 oct remainder 7

Reading up (1st division remainder is less sig. digit, and last is most sig.)
answer 7B hex


Register to reply

Related Discussions
Decimal to binary, Decimal to Octal confusion! Electrical Engineering 10
converting decimal to binary Calculus & Beyond Homework 5
Octal Multiplication confusion Engineering, Comp Sci, & Technology Homework 5
Questions about octal buffer Electrical Engineering 4
Question on binary stars & binary stars Introductory Physics Homework 1