A=1-1/2+1-1/4+1-1/8+1-1/16+.....+1-1/1024 =1+1+1+......+1-1/2-1/4-1/8-1/16-......-1/1024 =10-512/1024-256/1024-128/1024-......-1/1024 =10-1023/1024 =10-1+1/1024 =9+1/1024所以比A小的最大自然数是9
9
