1-1/2-1/4-1/8-1/16-1/32-1/64-1/128 =1/2-1/4-1/8-1/16-1/32-1/64-1/128 =1/4-1/8-1/16-1/32-1/64-1/128 … =1/64-1/128 =1/128
