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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)
27
×
33
(2)
22
×
18
(3)
69
×
71
(4)
53
×
47
(5)
2
28
(6)
2
32
(7)
67
×
73
(8)
2
43
(9)
99
×
101
(10)
2
71
(11)
71
×
69
(12)
2
48
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
27
×
33
2
2
=
(
30
−
3
)
(
30
+
3
)
=
30
−
3
=
900
−
9
=
891
(2)
22
×
18
2
2
=
(
20
+
2
)
(
20
−
2
)
=
20
−
2
=
400
−
4
=
396
(3)
69
×
71
2
2
=
(
70
−
1
)
(
70
+
1
)
=
70
−
1
=
4900
−
1
=
4899
(4)
53
×
47
2
2
=
(
50
+
3
)
(
50
−
3
)
=
50
−
3
=
2500
−
9
=
2491
(5)
2
28
2
2
2
=
(
30
−
2
)
=
30
−
2
×
30
×
2
+
2
=
900
−
120
+
4
=
784
(6)
2
32
2
2
2
=
(
30
+
2
)
=
30
+
2
×
30
×
2
+
2
=
900
+
120
+
4
=
1024
(7)
67
×
73
2
2
=
(
70
−
3
)
(
70
+
3
)
=
70
−
3
=
4900
−
9
=
4891
(8)
2
43
2
2
2
=
(
40
+
3
)
=
40
+
2
×
40
×
3
+
3
=
1600
+
240
+
9
=
1849
(9)
99
×
101
2
2
=
(
100
−
1
)
(
100
+
1
)
=
100
−
1
=
10000
−
1
=
9999
(10)
2
71
2
2
2
=
(
70
+
1
)
=
70
+
2
×
70
×
1
+
1
=
4900
+
140
+
1
=
5041
(11)
71
×
69
2
2
=
(
70
+
1
)
(
70
−
1
)
=
70
−
1
=
4900
−
1
=
4899
(12)
2
48
2
2
2
=
(
50
−
2
)
=
50
−
2
×
50
×
2
+
2
=
2500
−
200
+
4
=
2304