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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)
102
×
98
(2)
97
×
103
(3)
2
57
(4)
2
68
(5)
2
63
(6)
2
89
(7)
2
52
(8)
2
72
(9)
38
×
42
(10)
2
48
(11)
2
67
(12)
2
41
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
102
×
98
2
2
=
(
100
＋
2
)
(
100
−
2
)
=
100
−
2
=
10000
−
4
=
9996
(2)
97
×
103
2
2
=
(
100
−
3
)
(
100
＋
3
)
=
100
−
3
=
10000
−
9
=
9991
(3)
2
57
2
2
2
=
(
60
−
3
)
=
60
−
2
×
60
×
3
＋
3
=
3600
−
360
＋
9
=
3249
(4)
2
68
2
2
2
=
(
70
−
2
)
=
70
−
2
×
70
×
2
＋
2
=
4900
−
280
＋
4
=
4624
(5)
2
63
2
2
2
=
(
60
＋
3
)
=
60
＋
2
×
60
×
3
＋
3
=
3600
＋
360
＋
9
=
3969
(6)
2
89
2
2
2
=
(
90
−
1
)
=
90
−
2
×
90
×
1
＋
1
=
8100
−
180
＋
1
=
7921
(7)
2
52
2
2
2
=
(
50
＋
2
)
=
50
＋
2
×
50
×
2
＋
2
=
2500
＋
200
＋
4
=
2704
(8)
2
72
2
2
2
=
(
70
＋
2
)
=
70
＋
2
×
70
×
2
＋
2
=
4900
＋
280
＋
4
=
5184
(9)
38
×
42
2
2
=
(
40
−
2
)
(
40
＋
2
)
=
40
−
2
=
1600
−
4
=
1596
(10)
2
48
2
2
2
=
(
50
−
2
)
=
50
−
2
×
50
×
2
＋
2
=
2500
−
200
＋
4
=
2304
(11)
2
67
2
2
2
=
(
70
−
3
)
=
70
−
2
×
70
×
3
＋
3
=
4900
−
420
＋
9
=
4489
(12)
2
41
2
2
2
=
(
40
＋
1
)
=
40
＋
2
×
40
×
1
＋
1
=
1600
＋
80
＋
1
=
1681