脱式计算． 2.5×1.25×0.32 1.2×3.5÷1.2×3.5 23.4÷7.8-2.1 89.3×43+38×89.3+19×89.3．

①2.5×1.25×0.32
=2.5×1.25×0.4×0.8
=（2.5×0.4）×（1.25×0.8）
=1×2
=2

②1.2×3.5÷1.2×3.5
=（1.2÷1.2）×（3.5×3.5）
=1×12.25
=12.25

③23.4÷7.8-2.1
=3-2.1
=0.9

④89.3×43+38×89.3+19×89.3
=89.3×（43+38+19）
=89.3×100
=8930