Area = a7 / Screen = 4x4
  1x1   1x2   2x2   3x3   Now
AREA_a6 AREA_a7 AREA_a8 AREA_a9
AREA_b6 AREA_b7 AREA_b8 AREA_b9
AREA_c6 AREA_c7 AREA_c8 AREA_c9