Dammit! Someone wrote up the nodeshell before me. Ah well, I'll write my version, and they can fight it out.

Write your binary number down. Here's mine:

```11010111
```
Now, divide it up into groups of three, starting at the right. If the leftmost group has less than three letters in it, put zeroes at the start to make it up to three.

```011 010 111
```
Now, this is similar to Binary to Hexadecimal. For each group of three characters, write numbers underneath. Start at the right, with 1, then double it (2) and write that below the middle digit then double that (4) and write it below the leftmost digit. Example:

```011 010 111
421 421 421
```
Now multiply the top by the bottom for each digit, i.e.

```011 010 111
421 421 421
021 020 421
```
Next, go along the bottom line, adding together the groups of three numbers:
```021 020 021

0 + 2 + 1 = 3
0 + 2 + 0 = 2
4 + 2 + 1 = 7
3   2   7
```
These are the octal numbers for the little groups of three binary digits. Now, if we squash them into one long number:
```327
```
And there we have it; 11010111 Binary = 327 Octal

If you don't understand this, I'd check out my Binary to Hexadecimal node. It has better examples.