①28.4×99+28.4
②3.6×201
③0.25×(4+0.4)+0.9
④4×0.8×12.5×2.5
⑤4.8÷1.25÷0.8
3.7+5.6= 2.4÷0.08= += 8﹣= 0.23=
×6.4= ×= 3÷1%= 4a+a= 6×÷6×=
6.6×6.9=
6.66×66.9=
6.666×666.9=
6.6666×6666.9=
6.66666×66666.9=
2999.997÷9=
3999.996÷9=
4999.995÷9=
5999.994÷9=
6999.993÷9=