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我会用简便方法计算.25+3.56+135+6.441118×67+718÷7619.9+19.9×99.

题目详情
我会用简便方法计算.
2
5
+3.56+1
3
5
+6.44     
11
18
×
6
7
+
7
18
÷
7
6
     
19.9+19.9×99.
▼优质解答
答案和解析
(1)
2
5
+3.56+1
3
5
+6.44
=
2
5
+1
3
5
+(3.56+6.44)
=2+10
=12

(2)
11
18
×
6
7
+
7
18
÷
7
6

=
11
18
×
6
7
+
7
18
×
6
7

=(
11
18
+
7
18
)×
6
7

=1×
6
7

=
6
7


(3)19.9+19.9×99
=(1+99)×19.9
=100×19.9
=1990