问题
解答题
用简便方法计算: 26×
85×
|
答案
(1)26×
+18×5 43
-5 43
,5 43
=
×(26+18-1),5 43
=
×43,5 43
=5;
(2)85×
,5 42
=(84+1)×
,5 42
=84×
+1×5 42 5 42
=10+
,5 42
=10
.5 42
用简便方法计算: 26×
85×
|
(1)26×
+18×5 43
-5 43
,5 43
=
×(26+18-1),5 43
=
×43,5 43
=5;
(2)85×
,5 42
=(84+1)×
,5 42
=84×
+1×5 42 5 42
=10+
,5 42
=10
.5 42