①19×23=23×
②35×9×2=××9
③75×25×4=75×(×4)
④80×(5×)= ( 80×)×27
⑤(a×b)×c=a×(×)
⑥125×5×8×2=(125×)×(×)
只运用了乘法交换律的有,只运用了乘法结合律的有,既运用了乘法交换律又运用了乘法结合律的有。(填序号)
①18.4+2.78=
②4.02×1.8=
③3.82×0.45=