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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)
47
×
53
(2)
2
32
(3)
32
×
28
(4)
48
×
52
(5)
2
89
(6)
2
71
(7)
23
×
17
(8)
98
×
102
(9)
53
×
47
(10)
53
×
47
(11)
2
72
(12)
28
×
32
©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
32
2
2
2
=
(
30
＋
2
)
=
30
＋
2
×
30
×
2
＋
2
=
900
＋
120
＋
4
=
1024
(3)
32
×
28
2
2
=
(
30
＋
2
)
(
30
−
2
)
=
30
−
2
=
900
−
4
=
896
(4)
48
×
52
2
2
=
(
50
−
2
)
(
50
＋
2
)
=
50
−
2
=
2500
−
4
=
2496
(5)
2
89
2
2
2
=
(
90
−
1
)
=
90
−
2
×
90
×
1
＋
1
=
8100
−
180
＋
1
=
7921
(6)
2
71
2
2
2
=
(
70
＋
1
)
=
70
＋
2
×
70
×
1
＋
1
=
4900
＋
140
＋
1
=
5041
(7)
23
×
17
2
2
=
(
20
＋
3
)
(
20
−
3
)
=
20
−
3
=
400
−
9
=
391
(8)
98
×
102
2
2
=
(
100
−
2
)
(
100
＋
2
)
=
100
−
2
=
10000
−
4
=
9996
(9)
53
×
47
2
2
=
(
50
＋
3
)
(
50
−
3
)
=
50
−
3
=
2500
−
9
=
2491
(10)
53
×
47
2
2
=
(
50
＋
3
)
(
50
−
3
)
=
50
−
3
=
2500
−
9
=
2491
(11)
2
72
2
2
2
=
(
70
＋
2
)
=
70
＋
2
×
70
×
2
＋
2
=
4900
＋
280
＋
4
=
5184
(12)
28
×
32
2
2
=
(
30
−
2
)
(
30
＋
2
)
=
30
−
2
=
900
−
4
=
896