[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)
52
×
48
(2)
81
×
79
(3)
2
87
(4)
2
51
(5)
47
×
53
(6)
2
62
(7)
2
37
(8)
37
×
43
(9)
2
59
(10)
2
58
(11)
2
53
(12)
2
48
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
52
×
48
2
2
=
(
50
+
2
)
(
50
−
2
)
=
50
−
2
=
2500
−
4
=
2496
(2)
81
×
79
2
2
=
(
80
+
1
)
(
80
−
1
)
=
80
−
1
=
6400
−
1
=
6399
(3)
2
87
2
2
2
=
(
90
−
3
)
=
90
−
2
×
90
×
3
+
3
=
8100
−
540
+
9
=
7569
(4)
2
51
2
2
2
=
(
50
+
1
)
=
50
+
2
×
50
×
1
+
1
=
2500
+
100
+
1
=
2601
(5)
47
×
53
2
2
=
(
50
−
3
)
(
50
+
3
)
=
50
−
3
=
2500
−
9
=
2491
(6)
2
62
2
2
2
=
(
60
+
2
)
=
60
+
2
×
60
×
2
+
2
=
3600
+
240
+
4
=
3844
(7)
2
37
2
2
2
=
(
40
−
3
)
=
40
−
2
×
40
×
3
+
3
=
1600
−
240
+
9
=
1369
(8)
37
×
43
2
2
=
(
40
−
3
)
(
40
+
3
)
=
40
−
3
=
1600
−
9
=
1591
(9)
2
59
2
2
2
=
(
60
−
1
)
=
60
−
2
×
60
×
1
+
1
=
3600
−
120
+
1
=
3481
(10)
2
58
2
2
2
=
(
60
−
2
)
=
60
−
2
×
60
×
2
+
2
=
3600
−
240
+
4
=
3364
(11)
2
53
2
2
2
=
(
50
+
3
)
=
50
+
2
×
50
×
3
+
3
=
2500
+
300
+
9
=
2809
(12)
2
48
2
2
2
=
(
50
−
2
)
=
50
−
2
×
50
×
2
+
2
=
2500
−
200
+
4
=
2304