怎样简便怎样算.三克油.
问题描述：
怎样简便怎样算.三克油.
8.8－7.72＋10.2－2.28 0.25×39＋0.25
答
8.8-7.72+10.2-2.28
=(8.8+10.2)-(7.72+2.28)
=19-10
=9
0.25×39+0.25
=0.25×(39+1)
=0.25×40
=10