820÷(2×2) 42×9÷6 (305-274)×13
①(25.8+7.5)+2.5
②85.7﹣(15.3﹣4.8)
③158×[(27+54)÷9]
④88×125
⑤12×97+3
⑥273﹣64﹣36
3.26-1.53+6.74-3.47
99×87
25×16×125