6.8×9.970 5 60÷60
305-199= ×0= 31×197≈
3.5×0.2= 2.4×=
改正:
﹣0.5= +3= ×= 0.8×=
0.23+177%= 2.5×40= 1÷= ×÷×=
3.8+0.75= +0.625= ﹣= 2÷0.04= 0.45×80=
87﹣49= 450÷0.9= 34÷7= 6.25×40= 4.3×=