六年级简便计算9.8*65.2*1.25-12.5*0.625*18过程!急用!

这个还用过程？
9.8*65.2*1.25=798.7
12.5*0.625*18=140.625
798.7-140.625=658.075

题目是不是有问题啊，是不是这样的啊，9.8*62.5*1.25-12.5*0.625*18

=9.8*65.2*1.25-1.25*62.5*1.8
=1.25*(65.2*9.8-62.5*1.8)
=1.25*(638.96-112.5)
=1.25*526.46
=658.075
*表示乘号

题目好像打错了
把0.625换成0.652
=(0.98-0.18)*65.2*12.5
=0.8*12.5*65.2
=10*65.2
=652

9.8*62.5*1.25-12.5*0.625*18
=9.8*6.25*12.5-12.5*0.625*18
=12.5*(9.8*6.25-6.25*1.8)
=12.5*6.25*8
=12.5*8*6.25
=100*6.25
=625