+ = -= += -= +=
-= -= -= + = -=
+= -= += 1-= +=
1-= += -= -= +=
+= += += -= -=
-= -= += -= +=
-= += -= += -=
+= —= -= -= - =
+0.4= -0.5= 0.2+= 1-= +=
18×4= 130×5= 24×3= 2×380= 25×2=
150×6= 35+75= 200-20= 14×6= 280×3= 700-70= 102-20= 150+510= 65÷8= 17×5= 31×20= 50×90= 70×140= 40×800= 32×30=
21×40= 190×5= 30×15= 208×30= 180×50= 206×40= 720+32= 765-60= 210÷7= 3000