0.1-0.01= 6.8÷10%= 3.6÷0.12= 398÷42≈
0.22= × = 24÷ = ×4÷ ×4=
175120195186 47771984777200
10﹣0.9= 28+82= 20×5%= +×0=
4.8÷0.8= += ×= 1÷-1=