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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)
32
×
28
(2)
2
33
(3)
2
43
(4)
78
×
82
(5)
57
×
63
(6)
28
×
32
(7)
2
51
(8)
83
×
77
(9)
2
77
(10)
2
83
(11)
2
73
(12)
39
×
41
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
32
×
28
2
2
=
(
30
+
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(2)
2
33
2
2
2
=
(
30
+
3
)
=
30
+
2
×
30
×
3
+
3
=
900
+
180
+
9
=
1089
(3)
2
43
2
2
2
=
(
40
+
3
)
=
40
+
2
×
40
×
3
+
3
=
1600
+
240
+
9
=
1849
(4)
78
×
82
2
2
=
(
80
−
2
)
(
80
+
2
)
=
80
−
2
=
6400
−
4
=
6396
(5)
57
×
63
2
2
=
(
60
−
3
)
(
60
+
3
)
=
60
−
3
=
3600
−
9
=
3591
(6)
28
×
32
2
2
=
(
30
−
2
)
(
30
+
2
)
=
30
−
2
=
900
−
4
=
896
(7)
2
51
2
2
2
=
(
50
+
1
)
=
50
+
2
×
50
×
1
+
1
=
2500
+
100
+
1
=
2601
(8)
83
×
77
2
2
=
(
80
+
3
)
(
80
−
3
)
=
80
−
3
=
6400
−
9
=
6391
(9)
2
77
2
2
2
=
(
80
−
3
)
=
80
−
2
×
80
×
3
+
3
=
6400
−
480
+
9
=
5929
(10)
2
83
2
2
2
=
(
80
+
3
)
=
80
+
2
×
80
×
3
+
3
=
6400
+
480
+
9
=
6889
(11)
2
73
2
2
2
=
(
70
+
3
)
=
70
+
2
×
70
×
3
+
3
=
4900
+
420
+
9
=
5329
(12)
39
×
41
2
2
=
(
40
−
1
)
(
40
+
1
)
=
40
−
1
=
1600
−
1
=
1599