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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)
97
×
103
(2)
31
×
29
(3)
2
47
(4)
61
×
59
(5)
2
82
(6)
2
71
(7)
32
×
28
(8)
2
69
(9)
98
×
102
(10)
2
87
(11)
73
×
67
(12)
2
61
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
97
×
103
2
2
=
(
100
−
3
)
(
100
+
3
)
=
100
−
3
=
10000
−
9
=
9991
(2)
31
×
29
2
2
=
(
30
+
1
)
(
30
−
1
)
=
30
−
1
=
900
−
1
=
899
(3)
2
47
2
2
2
=
(
50
−
3
)
=
50
−
2
×
50
×
3
+
3
=
2500
−
300
+
9
=
2209
(4)
61
×
59
2
2
=
(
60
+
1
)
(
60
−
1
)
=
60
−
1
=
3600
−
1
=
3599
(5)
2
82
2
2
2
=
(
80
+
2
)
=
80
+
2
×
80
×
2
+
2
=
6400
+
320
+
4
=
6724
(6)
2
71
2
2
2
=
(
70
+
1
)
=
70
+
2
×
70
×
1
+
1
=
4900
+
140
+
1
=
5041
(7)
32
×
28
2
2
=
(
30
+
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(8)
2
69
2
2
2
=
(
70
−
1
)
=
70
−
2
×
70
×
1
+
1
=
4900
−
140
+
1
=
4761
(9)
98
×
102
2
2
=
(
100
−
2
)
(
100
+
2
)
=
100
−
2
=
10000
−
4
=
9996
(10)
2
87
2
2
2
=
(
90
−
3
)
=
90
−
2
×
90
×
3
+
3
=
8100
−
540
+
9
=
7569
(11)
73
×
67
2
2
=
(
70
+
3
)
(
70
−
3
)
=
70
−
3
=
4900
−
9
=
4891
(12)
2
61
2
2
2
=
(
60
+
1
)
=
60
+
2
×
60
×
1
+
1
=
3600
+
120
+
1
=
3721