①42×17÷7
②36×24﹣4
③(810﹣162)÷9
④515﹣15×3
①6.4×2.5×1.25
②8.5×98%
③÷4+×
④×
①1.25×3.2×2.5
②×[0.75﹣()]
③×()
④2022×
⑤55×102+646÷38