想想算算.(1629﹣780)÷(1.25×80);;×÷(5﹣5);;.
(13×0.58-4.87+0.42×13- 5.13) ×4.25
999×778+333×666
-(+)
0.5×1.6+0.5×26.4
×(+0.8÷)