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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)
61
×
59
(2)
2
53
(3)
2
49
(4)
2
79
(5)
38
×
42
(6)
2
31
(7)
89
×
91
(8)
2
53
(9)
2
83
(10)
2
77
(11)
39
×
41
(12)
38
×
42
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
61
×
59
2
2
=
(
60
＋
1
)
(
60
−
1
)
=
60
−
1
=
3600
−
1
=
3599
(2)
2
53
2
2
2
=
(
50
＋
3
)
=
50
＋
2
×
50
×
3
＋
3
=
2500
＋
300
＋
9
=
2809
(3)
2
49
2
2
2
=
(
50
−
1
)
=
50
−
2
×
50
×
1
＋
1
=
2500
−
100
＋
1
=
2401
(4)
2
79
2
2
2
=
(
80
−
1
)
=
80
−
2
×
80
×
1
＋
1
=
6400
−
160
＋
1
=
6241
(5)
38
×
42
2
2
=
(
40
−
2
)
(
40
＋
2
)
=
40
−
2
=
1600
−
4
=
1596
(6)
2
31
2
2
2
=
(
30
＋
1
)
=
30
＋
2
×
30
×
1
＋
1
=
900
＋
60
＋
1
=
961
(7)
89
×
91
2
2
=
(
90
−
1
)
(
90
＋
1
)
=
90
−
1
=
8100
−
1
=
8099
(8)
2
53
2
2
2
=
(
50
＋
3
)
=
50
＋
2
×
50
×
3
＋
3
=
2500
＋
300
＋
9
=
2809
(9)
2
83
2
2
2
=
(
80
＋
3
)
=
80
＋
2
×
80
×
3
＋
3
=
6400
＋
480
＋
9
=
6889
(10)
2
77
2
2
2
=
(
80
−
3
)
=
80
−
2
×
80
×
3
＋
3
=
6400
−
480
＋
9
=
5929
(11)
39
×
41
2
2
=
(
40
−
1
)
(
40
＋
1
)
=
40
−
1
=
1600
−
1
=
1599
(12)
38
×
42
2
2
=
(
40
−
2
)
(
40
＋
2
)
=
40
−
2
=
1600
−
4
=
1596