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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)
22
×
18
(2)
53
×
47
(3)
2
69
(4)
2
49
(5)
31
×
29
(6)
27
×
33
(7)
82
×
78
(8)
38
×
42
(9)
2
78
(10)
2
32
(11)
59
×
61
(12)
87
×
93
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
22
×
18
2
2
=
(
20
＋
2
)
(
20
−
2
)
=
20
−
2
=
400
−
4
=
396
(2)
53
×
47
2
2
=
(
50
＋
3
)
(
50
−
3
)
=
50
−
3
=
2500
−
9
=
2491
(3)
2
69
2
2
2
=
(
70
−
1
)
=
70
−
2
×
70
×
1
＋
1
=
4900
−
140
＋
1
=
4761
(4)
2
49
2
2
2
=
(
50
−
1
)
=
50
−
2
×
50
×
1
＋
1
=
2500
−
100
＋
1
=
2401
(5)
31
×
29
2
2
=
(
30
＋
1
)
(
30
−
1
)
=
30
−
1
=
900
−
1
=
899
(6)
27
×
33
2
2
=
(
30
−
3
)
(
30
＋
3
)
=
30
−
3
=
900
−
9
=
891
(7)
82
×
78
2
2
=
(
80
＋
2
)
(
80
−
2
)
=
80
−
2
=
6400
−
4
=
6396
(8)
38
×
42
2
2
=
(
40
−
2
)
(
40
＋
2
)
=
40
−
2
=
1600
−
4
=
1596
(9)
2
78
2
2
2
=
(
80
−
2
)
=
80
−
2
×
80
×
2
＋
2
=
6400
−
320
＋
4
=
6084
(10)
2
32
2
2
2
=
(
30
＋
2
)
=
30
＋
2
×
30
×
2
＋
2
=
900
＋
120
＋
4
=
1024
(11)
59
×
61
2
2
=
(
60
−
1
)
(
60
＋
1
)
=
60
−
1
=
3600
−
1
=
3599
(12)
87
×
93
2
2
=
(
90
−
3
)
(
90
＋
3
)
=
90
−
3
=
8100
−
9
=
8091