脱式计算.(能简算的要简算)(1)1020+270÷18-864(2) 2 3 ÷0.8× 3 4 (3)

2024-11-09 02:07:20
推荐回答(1个)
回答(1):

(1)1020+270÷18-864,
=1020+15-864,
=171;

(2)
2
3
÷0.8×
3
4

=
2
3
÷
4
5
×
3
4

=
2
3
×
5
4
×
3
4

=
5
8


(3)
1
8
+
5
7
+6.875+
2
7

=(
1
8
+6.875)+(
5
7
+
2
7
),
=(0.125+6.875)+1,
=7+1,
=8;

(4)0.25×64×125%,
=0.25×4×2×8×1.25,
=(0.25×4)×(8×1.25)×2,
=1×10×1,
=20;

(5)[
8
15
-(
7
12
-
2
5
)]×
15
14

=[
8
15
-
11
60
15
14

=
21
60
×
15
14

=
3
8


(6)6.35×0.75+4.65×75%-
3
4

=6.35×0.75+4.65×0.75-0.75,
=(6.35+4.65-1)×0.75,
=10×0.75,
=7.5.