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©2025 数学クラブ http://sugaku.club/
月 日( )
● 次の計算をしなさい
[1C1-00]
(1)
33
×
27
(2)
31
×
29
(3)
77
×
83
(4)
2
68
(5)
2
28
(6)
2
59
(7)
2
77
(8)
48
×
52
(9)
2
81
(10)
2
78
(11)
63
×
57
(12)
2
52
©2025 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
33
×
27
2
2
=
(
30
+
3
)
(
30
−
3
)
=
30
−
3
=
900
−
9
=
891
(2)
31
×
29
2
2
=
(
30
+
1
)
(
30
−
1
)
=
30
−
1
=
900
−
1
=
899
(3)
77
×
83
2
2
=
(
80
−
3
)
(
80
+
3
)
=
80
−
3
=
6400
−
9
=
6391
(4)
2
68
2
2
2
=
(
70
−
2
)
=
70
−
2
×
70
×
2
+
2
=
4900
−
280
+
4
=
4624
(5)
2
28
2
2
2
=
(
30
−
2
)
=
30
−
2
×
30
×
2
+
2
=
900
−
120
+
4
=
784
(6)
2
59
2
2
2
=
(
60
−
1
)
=
60
−
2
×
60
×
1
+
1
=
3600
−
120
+
1
=
3481
(7)
2
77
2
2
2
=
(
80
−
3
)
=
80
−
2
×
80
×
3
+
3
=
6400
−
480
+
9
=
5929
(8)
48
×
52
2
2
=
(
50
−
2
)
(
50
+
2
)
=
50
−
2
=
2500
−
4
=
2496
(9)
2
81
2
2
2
=
(
80
+
1
)
=
80
+
2
×
80
×
1
+
1
=
6400
+
160
+
1
=
6561
(10)
2
78
2
2
2
=
(
80
−
2
)
=
80
−
2
×
80
×
2
+
2
=
6400
−
320
+
4
=
6084
(11)
63
×
57
2
2
=
(
60
+
3
)
(
60
−
3
)
=
60
−
3
=
3600
−
9
=
3591
(12)
2
52
2
2
2
=
(
50
+
2
)
=
50
+
2
×
50
×
2
+
2
=
2500
+
200
+
4
=
2704