Discrete help, Without using base 10, convert 11011001_2 to base 8

Without using base 10, convert 11011001_2 to base 8
by _2 i mean 11011001(little 2)

convert to base 8

You do this one like converting to base 4, but in groups of 3

11 011 001

In base 2,

000 = 0
001 = 1
010 = 2
011 = 3
100 = 4
101 = 5
110 = 6
111 = 7

so in base eight, your number is

331 base 8

11011001

11 011 001

3 3 1

Just separate this out into segments of 3 as 8 = 2^3

I hope this helps