①÷×
②÷(+)
③(+-)÷
④×+×
⑤×38×15×
⑥(+)×3×9
①××
②×-×
③3.7×+1.3÷
④(+)×12
⑤+×
⑥2-÷
①
②6.875﹣
③372÷25÷0.4
④77×