Does anyone know how to Subtract and Add Octal??

[Kenster102.5]

So I know that Octal is Base 8 and is in 3 bit chunks(group of 3 numbers). I am wondering how do I subtract or add if the number is bigger then the base.
Here are 2 questions

365
+234


601
- 357

So someone please help me since, it is for my Grade 11 Engineering Class, and please Step by Step.
Thank you.

[rdrake]

Well, let's go through a simple question:
342 + 760

We set it up like normal:

code:

342 +760 ----

First we do 2 + 0, which is 2.

code:

342 +760 ----    2

Then we do 4 + 6 since there is no carry.

code:

1  342 +760 ----   22

There is a carry of 1, since 4 + 6 is 10 which is 2 greater than 8.

Then we do 3 + 7 + 1:

code:

11  342 +760 ----  322

3 + 7 + 1 is 11, which is 3 greater than 8. So we have a value of 3, and a carry of 1.

Since there's nothing left to add, we just add the carry of 1 and we're done.

code:

11  342 +760 ---- 1322

I'm quite sure subtraction works in a very similar way.

[Kenster102.5]

Thank you so much, I now understand it some what.