问题 解答题
下面各题,怎样算简便就怎样算.
3.7×
3
4
+5.3×0.75+
3
4

38×
3
37

9.9+99.9+999.9
6.8÷4-1.2×25%+4
2
5
×0.25
5
12
+
1
15
)×24×15.
答案

(1)3.7×

3
4
+5.3×0.75+
3
4

=0.75×(3.7+5.3+1)

=7.5;

(2)38×

3
37

=(37+1)×

3
37

=3+

3
37

=3

3
37

(3)9.9+99.9+999.9

=10+100+1000-0.1-0.1-0.1

=1110-0.3

=1109.7;

(4)6.8÷4-1.2×25%+4

2
5
×0.25

=6.8×0.25-1.2×0.25+4.4×0.25

=(6.8-1.2+4.4)×0.25

=10×0.25

=2.5;

(5)(

5
12
+
1
15
)×24×15

=

5
12
×24×15+
1
15
×24×15

=150+24

=174.

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