1.直接写出得数。 0.6×0.8=0.48 3×0.9=2.7 2.5×0.4=1 3.6×0.4=1.44 12.5×8=100 50×0.04=2 80×0.3=24 1.1×9=9.9 3.用简便方法计算下面各题。 1.25×3.4×8 2.56×2.4+7.44×2.4 =1.25×8×3.4 =(2.56+7.44)×2.4 =10×3.4 =10×2.4 =34 =24 3.58×101 4.5×6.3+0.55×63 =3.58×(100+1) =4.5×6.3+5.5×6.3 =3.58×100+3.58×1 =(4.5+5.5)×6.3 =358+3.58 =10×6.3 =361.58 =63