On 10-06-30 10:02 PM, David McGlone wrote:
Hi again
I'm trying to learn about octal numbers and I don't understand this:
Binary: 001000101111
breakdown: (001)= 1 (000)= 0 (101)=5 (111)=7
I know it's similar to unix permissions, but I'm not understanding where for
example: 111 = 7
In base 10, which you use every day, we go
0
1
2
3
4
5
6
7
8
9
10
The number 10 is the number of distinct digits we use.
In binary we only us two, 0 and 1, so 10 is 2 decimal
So we go
0 = 0 decimal
1 = 1 << important
10 = 2 << important
11 = 3
100 = 4 << important
101 = 5
110 = 6
111 = 7
So binary 111 is 4 + 2 + 1 = 7
Stephen
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