- = - = + = + = 3- =
53= + = = + - =
2- =
0.5×8= 3.6×0.4= 39.68×0= 7.6×1= 0.7×2.5×4=
4÷0.5= 12÷0.06= 12÷1.2= 3÷30= 7.5×1.2÷7.5×1.2=
1.5×1= 910÷70= 2.2﹣1.9= 6÷7= 435+199=
+= -= ÷= 20×= ×=