［文字サイズの変更］
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©2025 数学クラブ http://sugaku.club/
月 日（ ）
● 次の計算をしなさい
[1C0-10]
(1)
2
2
5.23
−
6.23
(2)
2
2
2.8
−
7.8
(3)
2
2
0.25
−
0.85
(4)
2
2
0.72
−
0.42
(5)
2
2
0.78
−
0.68
(6)
2
2
4.7
−
5.7
(7)
2
2
47.1
−
57.1
(8)
2
2
6.8
−
7.8
(9)
2
2
3.5
−
7.5
(10)
2
2
7.3
−
5.3
(11)
2
2
0.86
−
0.36
(12)
2
2
31.5
−
21.5
©2025 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
2
2
5.23
−
6.23
=
(
5.23
−
6.23
)
(
5.23
＋
6.23
)
=
−11.46
(2)
2
2
2.8
−
7.8
=
(
2.8
−
7.8
)
(
2.8
＋
7.8
)
=
−5
×
10.6
=
−53
(3)
2
2
0.25
−
0.85
=
(
0.25
−
0.85
)
(
0.25
＋
0.85
)
=
−0.6
×
1.1
=
−0.66
(4)
2
2
0.72
−
0.42
=
(
0.72
−
0.42
)
(
0.72
＋
0.42
)
=
0.3
×
1.14
=
0.342
(5)
2
2
0.78
−
0.68
=
(
0.78
−
0.68
)
(
0.78
＋
0.68
)
=
0.1
×
1.46
=
0.146
(6)
2
2
4.7
−
5.7
=
(
4.7
−
5.7
)
(
4.7
＋
5.7
)
=
−10.4
(7)
2
2
47.1
−
57.1
=
(
47.1
−
57.1
)
(
47.1
＋
57.1
)
=
−10
×
104.2
=
−1042
(8)
2
2
6.8
−
7.8
=
(
6.8
−
7.8
)
(
6.8
＋
7.8
)
=
−14.6
(9)
2
2
3.5
−
7.5
=
(
3.5
−
7.5
)
(
3.5
＋
7.5
)
=
−4
×
11
=
−44
(10)
2
2
7.3
−
5.3
=
(
7.3
−
5.3
)
(
7.3
＋
5.3
)
=
2
×
12.6
=
25.2
(11)
2
2
0.86
−
0.36
=
(
0.86
−
0.36
)
(
0.86
＋
0.36
)
=
0.5
×
1.22
=
0.61
(12)
2
2
31.5
−
21.5
=
(
31.5
−
21.5
)
(
31.5
＋
21.5
)
=
10
×
53
=
530