• 1. (2020五上·溧阳期中) 1-0.1=0.9

  1-0.1-0.01=0.89

  1-0.1-0.01-0.001 =0.889

  1-0.1-0.01-0.001-0.0001=

  1-0.1-0.01-0.001-0.0001-……- =