(344×2+212)÷9 640÷(564-406-150) 2×(150×2+105÷5) (281+127-298÷2)×2

(344•2+212):9=(688+212):9=900:9=100
640:(564-406-150)=640:8=80
2•(150•2+105:5)=2•(300+21)=2•321=642
(281+127-298:2)•2=(281+127-149)•2=259•2=518