6.8×9.970 5 60÷60
﹣0.5= +3= ×= 0.8×=
0.23+177%= 2.5×40= 1÷= ×÷×=
3.57+1.43= 4.2× =
10-9.2= 0.6×0.6=
0.72÷0.8= 8× ÷8÷ =