①6.4×2.5×1.25
②8.5×98%
③÷4+×
④×
①1204+879+121
②74×60%+×25+0.6
③1.2÷×(0.6﹣)
④×[﹣(+)]
①36×()
②1.3×37.5%+2.7×
③ [()]
④13÷()×