Question

用简便方法计算下题： 12.7-（3.7+0.84） 36.54-1.76-4.54 0.25×0.73×4 7.6×0.8+0.2×7.6 0.85×199

12.5×0.96×0.8 急急急急急急

Answer 1

12.7-（3.7+0.84）=(12.7-3.7)-0.84=9-0.84=8.16
36.54-1.76-4.54=(36.54-4.54)-1.76=32-1.76=30.24
0.25×0.73×4=(0.25*4)*0.73=1*0.73=0.73
7.6×0.8+0.2×7.6=7.6*(0.8+0.2)=7.6*1=7.6
0.85×199=0.85*(200-1)=0.85*200-0.85*1=170-0.85=169.15
12.5×0.96×0.8=(12.5*0.8)*0.96=10*0.96=9.6

Answer 2

12.7-(3.7+0.84)=(12.7-3.7)-0.84=9-0.84=8.16
36.54-1.76-4.54=(36.54-4.54)-1.76=30.24
0.25×0.73×4＝0.25×4×0.73＝1×0.73＝0.73
7.6×0.8+0.2×7.6＝7.6×（0.8+0.2）＝7.6×1＝7.6
0.85×199＝0.85×(200-1)=0.85×200-0.85×1=170-0.85=169.15
12.5×0.96×0.8=12.5×0.8×0.96=10×0.96=9.6

Answer 3

12.7-(3.7+0.84)=(12.7-3.7)-0.84
36.54-1.76-4.54=36.54-4.54-1.76
0.25*0.73*4=0.25*4*0.73
7.6*0.8+0.2*7.6=7.6*(0.8+0.2)
0.85*199=200*0.85-0.85
12.5*9.6*0.8=12.5*0.8*9.6