original bread is 10 X 12.5 X 2. so if you cut pieces 2 X 2.5X 2 you would take 1o inches divided by 2 inches = 5 pieces (long). 12.5 inches divided by 2.5 inches wide = 5 pieces (wide). The 2 inches high cancels itself out because the bread is 2 inches high to begin with. Therefore 5 X 5 = 25 or 25 total pieces of banana bread at 2" x 2.5" x 2".