67﹣40=
15×6=
3.5÷7=
16+25=
-=
÷=
×21=
+=
①(-+)×24
②14.86﹣(6.28+2.36)﹣3.72
③÷[÷(-)]
④2.4×3.6+3.2×4.8
⑤+++......++
⑥××18×24