①5- - =
② + + =
③ -2.75-(0.25+ )
④ + + +
⑤ -( + )
⑥ + +
2.5+0.5=
0.07×10=
1-0.25=
4.5-1.09=
0.4×5=
12.4n-4n=
0.16÷0.4=
2.4×0.5=
4÷0.05=
0.32=
①÷6+×
②-×
③(+)×36
④÷×
π
90
70
48
52
54