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©2026 数学クラブ http://sugaku.club/
月 日( )
● 次の計算をしなさい
[1C1-00]
(1)
2
81
(2)
2
67
(3)
59
×
61
(4)
72
×
68
(5)
2
41
(6)
39
×
41
(7)
2
81
(8)
2
42
(9)
2
41
(10)
93
×
87
(11)
2
43
(12)
2
27
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
2
81
2
2
2
=
(
80
+
1
)
=
80
+
2
×
80
×
1
+
1
=
6400
+
160
+
1
=
6561
(2)
2
67
2
2
2
=
(
70
−
3
)
=
70
−
2
×
70
×
3
+
3
=
4900
−
420
+
9
=
4489
(3)
59
×
61
2
2
=
(
60
−
1
)
(
60
+
1
)
=
60
−
1
=
3600
−
1
=
3599
(4)
72
×
68
2
2
=
(
70
+
2
)
(
70
−
2
)
=
70
−
2
=
4900
−
4
=
4896
(5)
2
41
2
2
2
=
(
40
+
1
)
=
40
+
2
×
40
×
1
+
1
=
1600
+
80
+
1
=
1681
(6)
39
×
41
2
2
=
(
40
−
1
)
(
40
+
1
)
=
40
−
1
=
1600
−
1
=
1599
(7)
2
81
2
2
2
=
(
80
+
1
)
=
80
+
2
×
80
×
1
+
1
=
6400
+
160
+
1
=
6561
(8)
2
42
2
2
2
=
(
40
+
2
)
=
40
+
2
×
40
×
2
+
2
=
1600
+
160
+
4
=
1764
(9)
2
41
2
2
2
=
(
40
+
1
)
=
40
+
2
×
40
×
1
+
1
=
1600
+
80
+
1
=
1681
(10)
93
×
87
2
2
=
(
90
+
3
)
(
90
−
3
)
=
90
−
3
=
8100
−
9
=
8091
(11)
2
43
2
2
2
=
(
40
+
3
)
=
40
+
2
×
40
×
3
+
3
=
1600
+
240
+
9
=
1849
(12)
2
27
2
2
2
=
(
30
−
3
)
=
30
−
2
×
30
×
3
+
3
=
900
−
180
+
9
=
729