864-278-122=864-( + ) 26×25=25×
125×9×8=××9 63×125-63×25=63×( )
547+39-147
45×[360÷(40-16)]
534-(134-60)
101×99
25×47-25×3
560÷35
验算
905﹣260= =
= =
1.25×2.5×32= 8÷0.01=
808÷88≈ 697+296≈