5.28+0.72*9用简便方法计算!_数学解答

5.28+0.72*9用简便方法计算!

人气：438 ℃　时间：2020-03-20 09:14:41

解答

5.28+0.72×9
=5.28+0.72×(10-1)
=5.28+0.72×10-0.72×1
=5.28+7.2-0.72
=12.48-0.72
=12.48-1+0.28
=11.48+0.28
=11.66