Similarly a "binary point" can be used to represent fractional values in binary:

   n = 1   1   0  = 1*4 + 1*2 + 0*1 = 6
       |   |   |
      22   21  20
        
   

If a number has a fractional part, the positions to the right of the binary point are also powers of 2, but they are negative powers:

   n = 1   1   0  .  1    1  =  1*4 + 1*2 + 0*1 + 1/2 + 1/4 = 6.75
       |   |   |     |    |
      22   21  20    2-1  2-2