早教吧 育儿知识 作业答案 考试题库 百科 知识分享

怎样简便怎样算.2.87+5.6-0.87+4.4(115+317)×15×171.7×1021.25×0.32×2503.5×45+5.5×80%+0.83.68-0.82-0.18.

题目详情
怎样简便怎样算.
2.87+5.6-0.87+4.4         
1
15
+
3
17
)×15×17
1.7×102                       
1.25×0.32×250
3.5×
4
5
+5.5×80%+0.8      
3.68-0.82-0.18.
▼优质解答
答案和解析
(1)2.87+5.6-0.87+4.4
=2.87-0.87+5.6+4.4
=(2.87-0.87)+(5.6+4.4)
=2+10
=12;

(2)(
1
15
+
3
17
)×15×17
=
1
15
×15×17+
3
17
×15×17
=17+45
=62;

(3)1.7×102
=1.7×(100+2)
=1.7×100+1.7×2
=170+3.4
=173.4;

(4)1.25×0.32×250
=1.25×0.8×0.4×250
=(1.25×0.8)×(0.4×250)
=1×100
=100;

(5)3.5×
4
5
+5.5×80%+0.8
=(3.5+5.5+1)×0.8
=10×0.8
=8;

(6)3.68-0.82-0.18
=3.68-(0.82+0.18)
=3.68-1
=2.68.