第一单元练习三1.在下面的 中填上适当的数。592.50.4= ( ) 7.815+2.215=( + )150.021.2558=( )( )2.把左右两边相等的式子用线连起来。(5+8)0.4 95+91.64.619+5.419 50.4+80.49(5+1.6)(4.6+5.4)193.642.53.6(42.5)3.用简便方法计算下面各题。2.5(3.80.04) 7.69101460.33+540.33 0.12572答案提示1.592.50.47.82.20.0251.2582.3.2.5(3.80.04)=2.50.043.8=0.13.8=0.387.69101=7.69(100+1)=776.69460.33+540.33=(46+54)0.33=1000.33=330.12572=0.12589=19=9