［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)
99
×
101
(2)
2
62
(3)
91
×
89
(4)
2
63
(5)
43
×
37
(6)
73
×
67
(7)
2
43
(8)
2
78
(9)
42
×
38
(10)
101
×
99
(11)
2
49
(12)
2
63
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
99
×
101
2
2
=
(
100
−
1
)
(
100
＋
1
)
=
100
−
1
=
10000
−
1
=
9999
(2)
2
62
2
2
2
=
(
60
＋
2
)
=
60
＋
2
×
60
×
2
＋
2
=
3600
＋
240
＋
4
=
3844
(3)
91
×
89
2
2
=
(
90
＋
1
)
(
90
−
1
)
=
90
−
1
=
8100
−
1
=
8099
(4)
2
63
2
2
2
=
(
60
＋
3
)
=
60
＋
2
×
60
×
3
＋
3
=
3600
＋
360
＋
9
=
3969
(5)
43
×
37
2
2
=
(
40
＋
3
)
(
40
−
3
)
=
40
−
3
=
1600
−
9
=
1591
(6)
73
×
67
2
2
=
(
70
＋
3
)
(
70
−
3
)
=
70
−
3
=
4900
−
9
=
4891
(7)
2
43
2
2
2
=
(
40
＋
3
)
=
40
＋
2
×
40
×
3
＋
3
=
1600
＋
240
＋
9
=
1849
(8)
2
78
2
2
2
=
(
80
−
2
)
=
80
−
2
×
80
×
2
＋
2
=
6400
−
320
＋
4
=
6084
(9)
42
×
38
2
2
=
(
40
＋
2
)
(
40
−
2
)
=
40
−
2
=
1600
−
4
=
1596
(10)
101
×
99
2
2
=
(
100
＋
1
)
(
100
−
1
)
=
100
−
1
=
10000
−
1
=
9999
(11)
2
49
2
2
2
=
(
50
−
1
)
=
50
−
2
×
50
×
1
＋
1
=
2500
−
100
＋
1
=
2401
(12)
2
63
2
2
2
=
(
60
＋
3
)
=
60
＋
2
×
60
×
3
＋
3
=
3600
＋
360
＋
9
=
3969