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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
68
(2)
32
×
28
(3)
2
61
(4)
91
×
89
(5)
72
×
68
(6)
2
89
(7)
2
33
(8)
78
×
82
(9)
2
79
(10)
47
×
53
(11)
29
×
31
(12)
88
×
92
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
2
68
2
2
2
=
(
70
−
2
)
=
70
−
2
×
70
×
2
＋
2
=
4900
−
280
＋
4
=
4624
(2)
32
×
28
2
2
=
(
30
＋
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(3)
2
61
2
2
2
=
(
60
＋
1
)
=
60
＋
2
×
60
×
1
＋
1
=
3600
＋
120
＋
1
=
3721
(4)
91
×
89
2
2
=
(
90
＋
1
)
(
90
−
1
)
=
90
−
1
=
8100
−
1
=
8099
(5)
72
×
68
2
2
=
(
70
＋
2
)
(
70
−
2
)
=
70
−
2
=
4900
−
4
=
4896
(6)
2
89
2
2
2
=
(
90
−
1
)
=
90
−
2
×
90
×
1
＋
1
=
8100
−
180
＋
1
=
7921
(7)
2
33
2
2
2
=
(
30
＋
3
)
=
30
＋
2
×
30
×
3
＋
3
=
900
＋
180
＋
9
=
1089
(8)
78
×
82
2
2
=
(
80
−
2
)
(
80
＋
2
)
=
80
−
2
=
6400
−
4
=
6396
(9)
2
79
2
2
2
=
(
80
−
1
)
=
80
−
2
×
80
×
1
＋
1
=
6400
−
160
＋
1
=
6241
(10)
47
×
53
2
2
=
(
50
−
3
)
(
50
＋
3
)
=
50
−
3
=
2500
−
9
=
2491
(11)
29
×
31
2
2
=
(
30
−
1
)
(
30
＋
1
)
=
30
−
1
=
900
−
1
=
899
(12)
88
×
92
2
2
=
(
90
−
2
)
(
90
＋
2
)
=
90
−
2
=
8100
−
4
=
8096