计算下列各题,要写出主要计算过程,能用简便方法的要用简便方法计算. ①16×18-120÷15 ②3.2×2.

2024-12-16 17:59:20
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回答1:


①16×18-120÷15,
=288-8,
=280;

②3.2×2.77+0.23×3.2,
=3.2×(2.77+0.23),
=3.2×3,
=9.6;

③7.6-2.05÷0.82,
=7.6-2.5,
=5.1;

7
8
-
5
17
+
9
8
-
12
17

=(
7
8
+
9
8
)-(
5
17
+
12
17
),
=2-1,
=1;

2
9
-
7
16
×
2
9

=
2
9
×(1-
7
16
),
=
2
9
×
9
16

=
1
8


⑥13÷(
1
4
+
5
6
)×
3
4

=13÷
13
12
×
3
4

=12×
3
4

=9.