1.3×2.8= 0.13×0.28= 36.4÷2.8=
2.4×5= 0.22×5= 1-0.85= 2.3×4.1+5.7=
22.6-3.4-2.6= 12÷0.01 = 0÷0.42= 2.4a+6a=
0.85+0.25= 0.1×0.1+0.1×0.1=
+x=18
x×=18
-x=18
÷x=18