I mean not really cause base one would just be 111 + 111 = 111111. On the other hand if its baseless it still doesnt work cause then its 3 + 6 = 9? But with that it could just be base 10. One thing that could work is that its actually a split base 4 and 8 system where the first 3 digits of a number are base 4 and the rest are base 8 but this is a very confusing system and the opposite of what is usual. It could also be a system where 1, 2, 3 are used for whole parts of numbers and 4, 5, 6 were added when they inveneted fractions so they represent the fractional part of numbers? Thats what im gonna put my money on tho im probably ignoring something obvious.