28 into 12 best min fragment found: 5
  Cut up 28 sticks of length 12 like this:
    4 x (6 + 6)
    24 x (5 + 7)
  Reassemble as 12 sticks of length 28 like this:
    4 x (7 + 7 + 7 + 7)
    8 x (5 + 5 + 5 + 6 + 7)