540000,520000,500000,,,440000
2120819212□829 8570万8亿 5×4□21□9÷19
(320×3)÷8=
(320×2)÷(8×2)=
(320÷4)÷8=
(320÷4)÷(8÷4)=
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=