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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)
17
×
23
(2)
89
×
91
(3)
28
×
32
(4)
2
62
(5)
2
69
(6)
2
81
(7)
2
39
(8)
32
×
28
(9)
62
×
58
(10)
2
67
(11)
37
×
43
(12)
22
×
18
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
17
×
23
2
2
=
(
20
−
3
)
(
20
＋
3
)
=
20
−
3
=
400
−
9
=
391
(2)
89
×
91
2
2
=
(
90
−
1
)
(
90
＋
1
)
=
90
−
1
=
8100
−
1
=
8099
(3)
28
×
32
2
2
=
(
30
−
2
)
(
30
＋
2
)
=
30
−
2
=
900
−
4
=
896
(4)
2
62
2
2
2
=
(
60
＋
2
)
=
60
＋
2
×
60
×
2
＋
2
=
3600
＋
240
＋
4
=
3844
(5)
2
69
2
2
2
=
(
70
−
1
)
=
70
−
2
×
70
×
1
＋
1
=
4900
−
140
＋
1
=
4761
(6)
2
81
2
2
2
=
(
80
＋
1
)
=
80
＋
2
×
80
×
1
＋
1
=
6400
＋
160
＋
1
=
6561
(7)
2
39
2
2
2
=
(
40
−
1
)
=
40
−
2
×
40
×
1
＋
1
=
1600
−
80
＋
1
=
1521
(8)
32
×
28
2
2
=
(
30
＋
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(9)
62
×
58
2
2
=
(
60
＋
2
)
(
60
−
2
)
=
60
−
2
=
3600
−
4
=
3596
(10)
2
67
2
2
2
=
(
70
−
3
)
=
70
−
2
×
70
×
3
＋
3
=
4900
−
420
＋
9
=
4489
(11)
37
×
43
2
2
=
(
40
−
3
)
(
40
＋
3
)
=
40
−
3
=
1600
−
9
=
1591
(12)
22
×
18
2
2
=
(
20
＋
2
)
(
20
−
2
)
=
20
−
2
=
400
−
4
=
396