I have been messing with this small code for over an hour but it keeps adding 512 to my number on the first time adding the numbers

Question

number= str(123)
length=len(number)
baseTen=0
num=0
for i in number:
    num=(int(i)*8**length)
    print(baseTen)
    baseTen=baseTen+num #<------this is the iss