1 ÷11 =0.090909…… 10÷11 =
2÷11 =0.181818…… 11 ÷11 =
3 ÷11 =0.272727…… 12 ÷11 =
4÷11 =0.363636…… 13 ÷11 =
①
②7.5×8×12.5
③
④193﹣16﹣84