脱式计算,能简算的要简算.①480-48+124 ②1.25×3.2×0.25 ③(723+13)×3+223 ④(23-25)×30

2025-04-07 10:10:42
推荐回答(1个)
回答1:

(1)480-48+124,
=432+124,
=556;

(2)1.25×3.2×0.25,
=(1.25×8)×(0.4×0.25),
=10×0.1,
=1;

(3)(

7
23
+
1
3
)×3+
2
23

=
7
23
×
3+
1
3
×
3+
2
23

=(
21
23
+
2
23
)+1,
=1+1,
=2;

(4)(
2
3
-
2
5
)×30,
=
2
3
×
30-
2
5
×
30,
=20-12,
=8;

(5)3.45÷[0.3×(2.3-1.8)],
=3.45÷[0.3×0.5],
=3.45÷0.15,
=23;

(6)
2
3
×[(
1
3
-
1
5
)÷
4
5
],
=
2
3
×
[
2
15
÷
4
5
],
=
2
3
×
1
6

=
1
9