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)
0.5+2.3= 120÷30= 7.2+0.8= 4.3-1.2=
2-0.7= 2.4-1.6= 24×5= 0.3+0.47=
240÷6= 1.3-0.6= 2.3+5.7= 360-360÷6=
145+398= 6-0.6= 0.24×50= 3﹣3÷7= (+)×56=
1.25×6×8= = = ÷0.75= ×4÷×4=