0.21÷0.3= 6+3.4= 0.82-0.42= 0.046×100=
0.9-0.09= 0.77+0.3= 80+1000= 4n+5n-8n=
0.84÷2.8= 0.16×5= 0.32= 0.5×3÷0.5×3=