①68-19+25
②42÷6×8
③81-(40-24)
④64-56÷7
⑤53+3×9
⑥(18+36)÷9
□×□=□
□÷□=□
72÷9×7
4×(12-6)
45-17+33
2905>295 34<534 7050>051