28 into 20 best min fragment found: 20/3
  Cut up 28 sticks of length 20 like this:
    8 x (28/3 + 32/3)
    8 x (8 + 12)
    12 x (20/3 + 20/3 + 20/3)
  Reassemble as 20 sticks of length 28 like this:
    4 x (20/3 + 32/3 + 32/3)
    8 x (20/3 + 28/3 + 12)
    8 x (20/3 + 20/3 + 20/3 + 8)