试题:
简便计算.
7
4
+
3
7
+
1
4

1.25×8.8
2.5×37+6.3×25.

答案:

我来补答
(1)
7
4
+
3
7
+
1
4

=(
7
4
+
1
4
)+
3
7

=2+
3
7

=2
3
7


(2)1.25×8.8,
=1.25×(8+0.8),
=1.25×8+1.25×0.8,
=10+1,
=11;

(3)2.5×37+6.3×25,
=2.5×37+63×2.5,
=(37+63)×2.5,
=100×2.5,
=250.
 
 
展开全文阅读
剩余:2000
这些题目你会做吗?