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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
39
(2)
29
×
31
(3)
2
38
(4)
2
33
(5)
102
×
98
(6)
2
38
(7)
99
×
101
(8)
89
×
91
(9)
2
88
(10)
2
73
(11)
32
×
28
(12)
2
63
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
2
39
2
2
2
=
(
40
−
1
)
=
40
−
2
×
40
×
1
＋
1
=
1600
−
80
＋
1
=
1521
(2)
29
×
31
2
2
=
(
30
−
1
)
(
30
＋
1
)
=
30
−
1
=
900
−
1
=
899
(3)
2
38
2
2
2
=
(
40
−
2
)
=
40
−
2
×
40
×
2
＋
2
=
1600
−
160
＋
4
=
1444
(4)
2
33
2
2
2
=
(
30
＋
3
)
=
30
＋
2
×
30
×
3
＋
3
=
900
＋
180
＋
9
=
1089
(5)
102
×
98
2
2
=
(
100
＋
2
)
(
100
−
2
)
=
100
−
2
=
10000
−
4
=
9996
(6)
2
38
2
2
2
=
(
40
−
2
)
=
40
−
2
×
40
×
2
＋
2
=
1600
−
160
＋
4
=
1444
(7)
99
×
101
2
2
=
(
100
−
1
)
(
100
＋
1
)
=
100
−
1
=
10000
−
1
=
9999
(8)
89
×
91
2
2
=
(
90
−
1
)
(
90
＋
1
)
=
90
−
1
=
8100
−
1
=
8099
(9)
2
88
2
2
2
=
(
90
−
2
)
=
90
−
2
×
90
×
2
＋
2
=
8100
−
360
＋
4
=
7744
(10)
2
73
2
2
2
=
(
70
＋
3
)
=
70
＋
2
×
70
×
3
＋
3
=
4900
＋
420
＋
9
=
5329
(11)
32
×
28
2
2
=
(
30
＋
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(12)
2
63
2
2
2
=
(
60
＋
3
)
=
60
＋
2
×
60
×
3
＋
3
=
3600
＋
360
＋
9
=
3969