67﹣40=
15×6=
3.5÷7=
16+25=
-=
÷=
×21=
+=
①3.9×2.5×4
② ÷[ ×( - )]
③ × + ÷
①99.7×13+ ×13
②12.78﹣(1.17+2.78)﹣3.83
③910÷1.3×0.7
④67× ﹣9÷1.25+ ×2
12.8+4.5×3.6
15.5﹣(5.45﹣2.38)
45.5÷2.5÷4
我补充的条件是: