0.1×0.2×0.3×0.4×0.5×0.6×0.7×0.8×0.9怎么巧算

问题描述:

0.1×0.2×0.3×0.4×0.5×0.6×0.7×0.8×0.9怎么巧算

化为分数,即1/10*2/10*3/10*4*10*5/10*6/10*7/10*8/10*9/10=1/10*1/5*3/10*1/5*3/5*7/10*2/5*9/5=1/10*1/5*3/10*1/5*3/5*7/5*1/5*9/5=(81*7)/(25*25*25*100)=567/1562500=0.00036288