用简便方法计算. 18×5.25+3.75÷8+18 45

用简便方法计算. 18×5.25+3.75÷8+18 45+945+9945+99945+999945.
2025-03-10 19:49:58
推荐回答(1个)
回答1:


(1)
1
8
×5.25+3.75÷8+
1
8

=
1
8
×5.25+3.75×
1
8
+
1
8

=(5.25+3.75+1)×
1
8

=10×
1
8

=1.25;

(2)
4
5
+9
4
5
+99
4
5
+999
4
5
+9999
4
5

=(
1
5
+
1
5
+
1
5
+
1
5
)+9
4
5
+99
4
5
+999
4
5
+9999
4
5

=(9
4
5
+
1
5
)+(99
4
5
+
1
5
)+(999
4
5
+
1
5
)+(9999
4
5
+
1
5
),
=10+100+1000+10000,
=11110.