1.2×1.4≈1.7; 1.2 ×1.4 4 8 1 2 1.6 8 ;0.38×8.7≈3.3; 0.3 8 × 8.7 26 6 3 04 3.30 6 ;0.87×1.5≈1.31; 0.87 × 1.5 43 5 87 1.30 5 ;2.36×0.63≈1.49; 2.36 × 0.63 7 08 1 41 6 1.48 68 .