口算．
18×3= 120×5= 290×3= 4000÷8=
5×37= 42×20= 420÷7= 29×3=
4×160= 270×3= 670+28= 872﹣200=
20×41= 30×25= 4×230= 170×5=
口算．
3.2×0.2 1.4×0.4 3.3÷3 1.2÷0.3 5.6÷0.4
2.5×0.4 1.5×2 7.3+2.7 8.4÷0.7 4.5÷0.9
0.53﹣0.3 7.8÷6 8.4÷0.21 0.6×0.5 8.1×2
5.6+3.6 9﹣2.350.56÷8 1.23×3 12.5÷0.1．
直接写得数．
2.5×4= 0.25×3= 2.8×0.2= 2.4÷0.3= 4.6÷0.2=
0.32÷0.08= 7.2÷0.6= 0.06×15= 0.25×4×0.4= 7×2.6+7×0.4=
竖式计算，得数保留两位小数．
0.38×0.65 6.18×0.99 4.8÷2.3 23.5÷0.18．
列竖式计算，除法保留两位小数．
9.75×1.5 1÷6 13÷2.4 0.59×0.27．
用竖式计算．
3.49+2.15 7.4﹣3.68 5.3×0.26 0.453÷0.15．