早教吧 育儿知识 作业答案 考试题库 百科 知识分享

下列各题,怎么算简便就怎么算∴4.7×4.7+4.7×6.3-4.712.5×3.2×0.254.65×32+2.5×46.5+0.465×4307.25×67.875+725×0.7875+7250×0.05337550.1+0.3+0.5+0.7+0.9+0.11+0.13+0.15+0.17+0.19+…+0.99.

题目详情
下列各题,怎么算简便就怎么算∴
4.7×4.7+4.7×6.3-4.7
12.5×3.2×0.25    
4.65×32+2.5×46.5+0.465×430
7.25×67.875+725×0.7875+7250×0.0533755
0.1+0.3+0.5+0.7+0.9+0.11+0.13+0.15+0.17+0.19+…+0.99.
▼优质解答
答案和解析
(1)4.7×4.7+4.7×6.3-4.7
=4.7×(4.7+6.3-1)
=4.7×10
=47;
(2)12.5×3.2×0.25    
=(12.5×0.8)×(4×0.25)
=10×1
=10;
(3)4.65×32+2.5×46.5+0.465×430
=4.65×32+25×4.65+4.65×43
=4.65×(32+25+43)
=4.65×100
=465;
(4)7.25×67.875+725×0.7875+7250×0.0533755
=7.25×(67.875+78.75+53.3755)
=7.25×200.0005
=1450.00362;
(5)0.1+0.3+0.5+0.7+0.9+0.11+0.13+0.15+0.17+0.19+…+0.99
=(0.1+0.99)×50÷2
=1.09×50÷2
=27.25.