8.9×1.58.9 2.8÷0.92.8
8.74÷0.978.74×0.97 7.5÷0.257.5×4
8.9÷5.6的商与5.6÷8.9的商相乘积是1.
0.03+0.52= 3-0.3= 2.5×0.4= 0.4×0.7=