×6=
0.5t:200kg=
24×÷24×=
÷0.3=
20÷=
0.5-÷2=
:( )=
X-80%X=0.4
X+ =
X+ 25%X=25
÷= ×8= ÷14= ÷=
×= ×= 0×= ÷=