①520﹣450÷15
②1.2+4.92÷2.4
③0.8××12.5
④12÷×﹣
⑤(2.1+6.9÷0.15)÷0.1
⑥(0.25×3.2+0.8)×
⑦0.25÷(﹣)×2.4
( ﹣ )×18
÷ ÷
2.6× +2.4÷
1﹣ ÷( + )
+= 3﹣= ×= ÷=
+= -= ÷51= ×5.6=
1.5×80= ÷2= ×= ÷0.125=