［文字サイズの変更］
▼
▲
©2026 数学クラブ http://sugaku.club/
月 日（ ）
● 次の計算をしなさい
[1C1-00]
(1)
2
47
(2)
2
71
(3)
18
×
22
(4)
2
49
(5)
89
×
91
(6)
32
×
28
(7)
87
×
93
(8)
47
×
53
(9)
19
×
21
(10)
73
×
67
(11)
2
82
(12)
2
22
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
2
47
2
2
2
=
(
50
−
3
)
=
50
−
2
×
50
×
3
＋
3
=
2500
−
300
＋
9
=
2209
(2)
2
71
2
2
2
=
(
70
＋
1
)
=
70
＋
2
×
70
×
1
＋
1
=
4900
＋
140
＋
1
=
5041
(3)
18
×
22
2
2
=
(
20
−
2
)
(
20
＋
2
)
=
20
−
2
=
400
−
4
=
396
(4)
2
49
2
2
2
=
(
50
−
1
)
=
50
−
2
×
50
×
1
＋
1
=
2500
−
100
＋
1
=
2401
(5)
89
×
91
2
2
=
(
90
−
1
)
(
90
＋
1
)
=
90
−
1
=
8100
−
1
=
8099
(6)
32
×
28
2
2
=
(
30
＋
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(7)
87
×
93
2
2
=
(
90
−
3
)
(
90
＋
3
)
=
90
−
3
=
8100
−
9
=
8091
(8)
47
×
53
2
2
=
(
50
−
3
)
(
50
＋
3
)
=
50
−
3
=
2500
−
9
=
2491
(9)
19
×
21
2
2
=
(
20
−
1
)
(
20
＋
1
)
=
20
−
1
=
400
−
1
=
399
(10)
73
×
67
2
2
=
(
70
＋
3
)
(
70
−
3
)
=
70
−
3
=
4900
−
9
=
4891
(11)
2
82
2
2
2
=
(
80
＋
2
)
=
80
＋
2
×
80
×
2
＋
2
=
6400
＋
320
＋
4
=
6724
(12)
2
22
2
2
2
=
(
20
＋
2
)
=
20
＋
2
×
20
×
2
＋
2
=
400
＋
80
＋
4
=
484