7.8*9.9+0.78的简便计算该怎么算?

是简便计算,不是递等式计算哦!
2024-11-03 19:57:01
推荐回答(5个)
回答1:

0.78=?
0.78=7.8*0.1!!!
然后干嘛?
提取公因式

回答2:

7.8*9.9+0.78
=7.8*9.9+7.8*0.1
=7.8*(9.9+0.1)
=7.8*10
=78

回答3:

=7.8*(10-0.1)+0.78
=78-0.78+0.78
=78

回答4:

7.8*9.9+0.78
=7.8*(10-0.1)+0.78
=78-0.78+0.78
=78

回答5:

0.78(10*9.9+1)
=0.78(99+1)
=0.78*100
78