[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)
47
×
53
(2)
2
88
(3)
2
62
(4)
2
82
(5)
79
×
81
(6)
21
×
19
(7)
2
61
(8)
2
82
(9)
2
89
(10)
32
×
28
(11)
2
43
(12)
2
48
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
47
×
53
2
2
=
(
50
−
3
)
(
50
+
3
)
=
50
−
3
=
2500
−
9
=
2491
(2)
2
88
2
2
2
=
(
90
−
2
)
=
90
−
2
×
90
×
2
+
2
=
8100
−
360
+
4
=
7744
(3)
2
62
2
2
2
=
(
60
+
2
)
=
60
+
2
×
60
×
2
+
2
=
3600
+
240
+
4
=
3844
(4)
2
82
2
2
2
=
(
80
+
2
)
=
80
+
2
×
80
×
2
+
2
=
6400
+
320
+
4
=
6724
(5)
79
×
81
2
2
=
(
80
−
1
)
(
80
+
1
)
=
80
−
1
=
6400
−
1
=
6399
(6)
21
×
19
2
2
=
(
20
+
1
)
(
20
−
1
)
=
20
−
1
=
400
−
1
=
399
(7)
2
61
2
2
2
=
(
60
+
1
)
=
60
+
2
×
60
×
1
+
1
=
3600
+
120
+
1
=
3721
(8)
2
82
2
2
2
=
(
80
+
2
)
=
80
+
2
×
80
×
2
+
2
=
6400
+
320
+
4
=
6724
(9)
2
89
2
2
2
=
(
90
−
1
)
=
90
−
2
×
90
×
1
+
1
=
8100
−
180
+
1
=
7921
(10)
32
×
28
2
2
=
(
30
+
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(11)
2
43
2
2
2
=
(
40
+
3
)
=
40
+
2
×
40
×
3
+
3
=
1600
+
240
+
9
=
1849
(12)
2
48
2
2
2
=
(
50
−
2
)
=
50
−
2
×
50
×
2
+
2
=
2500
−
200
+
4
=
2304