4: 40×35 =1400平方厘米 =14平方分米 5: ﹙0.6×0.3+0.6×1.8+0.3×1.8﹚×2 =﹙0.18+1.08+0.54﹚×2 =3.6 6: 图1 42×3.14×2+3.14×4×2×12 =16×3.14×2+3.14×4×2×12 =100.48+301.44 =401.92 图2 40÷2=20 202×3.14+3.14×40×50 =400×3.14+3.14×40×50 =1256+6280 =7536 图3 0.638×1.2 =0.7536 7: 40cm=0.4m 5×1.8×0.4×1.5 =5.4 8: 6.28÷3.14÷2=1 12×3.14×6.28 =19.7192 9: 12.56÷3.14÷2=2 22×3.14×1.5÷3×750 =4×3.14×1.5÷3×750 =4710千克 =4.71吨 |