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用简便方法计算下面各题.(1)(15+27)×5×7(2)99989+9989+989+13(3)44445×1.25(4)231÷231231232.

编辑:chaxungu时间:2026-04-27 14:17:47分类:小学数学题库

用简便方法计算下面各题.
(1)(
1
5
+
2
7
)×5×7
(2)999
8
9
+99
8
9
+9
8
9
+
1
3

(3)444
4
5
×1.25
(4)231÷231
231
232
(1)(
1
5
+
2
7
)×5×7
=
1
5
×5×7+
2
7
×5×7,
=7+10,
=17;

(2)999
8
9
+99
8
9
+9
8
9
+
1
3

=(1000-
1
9
)+(100-
1
9
)+(10-
1
9
)+
1
3

=(1000+100+10)-
1
9
×3+
1
3

=1110-(
1
3
-
1
3
),
=1110;

(3)444
4
5
×1.25
=(444+
4
5
)×
5
4

=444×
5
4
+
4
5
×
5
4

=555+1,
=556;

(4)231÷231
231
232

=231÷
232×231+231
232

=231×
232
(232+1)×231

=
232
233