2222×17+3333×4+6666×9
7.68﹣3.56+2.32﹣5.44
1.25×3.2×0.25   
（0.625×6.8+0.625×4.2﹣0.625）÷0.625
300÷0.125÷0.8        
4000﹣1﹣2﹣3﹣…﹣77﹣78．