42.4+7.6= 1.58+2.42= 23.5+76.5÷0.25= 7.8﹣5.6=
1.25×4= 34.6÷0.2×4= 0.24÷0.3= 7.8×0.5=
1÷0.2﹣1×0.2= 57÷5.7= 8.1﹣0.05= 0.2×0.5=
27+0.73= 2.35﹣2.3= 0.15×4=
0.2×7.8×0.5= 6×0.4= 0.125×8=
7.2÷0.9= 9.3÷0.03= 0÷2.1×6.5=
1÷0.2÷0.5= 130×5= 280÷0.7= ．
0.72÷36= 5.2÷13= 0.87÷87= 9.6÷0.4=
0.27×4= 16×0.01= 0.27﹣0.09= 3.7×0.5×4=
0.036÷0.2= 5+0÷5﹣5=（9.7﹣9.7）×3.7= 1÷0.1﹣9×0.1=
口算．
0.4×0.25= 3.2÷0.8= 1.25×7×0.8= 1÷8=
0.2×0.9+0.6×0.2= 6.2÷0.62= 2﹣2÷5= 1﹣0.08=
0.5×0.1÷0.5×0.1= 0.01÷0.001×0.1=