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神机妙算细又巧!(1)29÷827×215(2)(14+310)÷34(3)56×14+16÷4(4)1836÷[56×(47-14)](5)11×2+12×3+…+198×99+199×100.

题目详情
神机妙算细又巧!
(1)
2
9
÷
8
27
×
2
15

(2)(
1
4
+
3
10
)÷
3
4

(3)
5
6
×
1
4
+
1
6
÷4
(4)1836÷[56×(
4
7
-
1
4
)]
(5)
1
1×2
+
1
2×3
+…+
1
98×99
+
1
99×100
▼优质解答
答案和解析
(1)
2
9
÷
8
27
×
2
15

=
2
9
×
27
8
×
2
15

=
1
10

(2)(
1
4
+
3
10
)÷
3
4

=
1
4
÷
3
4
+
3
10
÷
3
4

=
1
4
×
4
3
+
3
10
×
4
3

=
1
3
+
2
5

=
5
15
+
6
15

=
11
15

(3)
5
6
×
1
4
+
1
6
÷4,
=
5
6
×
1
4
+
1
6
×
1
4

=(
5
6
+
1
6
)×
1
4

=1×
1
4

=
1
4

(4)1836÷[56×(
4
7
-
1
4
)],
=1836÷[56×
4
7
-56×
1
4
],
=1836÷[32-14],
=1836÷18,
=102;
(5)
1
1×2
+
1
2×3
+…+
1
98×99
+
1
99×100

=(
1
1
1
2
)+(
1
2
1
3
)+…+(
1
98
1
99
)+(
1
99
1
100
),
=1-
1
100

=
99
100