早教吧 育儿知识 作业答案 考试题库 百科 知识分享

1、19...9(2005个)+99...99(2005个)*99...99(2005个)2、3.6*31.4+43.9*6.43、41.2*8.1+11*9.25+537*0.194、88...88(2010个)*99...99(2010个)+33...33(2010个)*33...33(2009个)65、(1+0.23+0.34)*(0.23+0.34+0.65)-(1

题目详情
1、19...9(2005个)+99...99(2005个)*99...99(2005个)
2、3.6*31.4+43.9*6.4
3、41.2*8.1+11*9.25+537*0.19
4、88...88(2010个)*99...99(2010个)+33...33(2010个)*33...33(2009个)6
5、(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)
5、12.34+23.45+34.56+45.67+56.78+67.89+78.91.89.12.91.23
6、【(35.16*0.25+38.42/2)*0.2-1.63-2.36】/0.25
7、124.68+324.68+524.68+724.68+924.68
8、0.1+0.3+...+0.99
不要用计算机!(有技巧的算)
▼优质解答
答案和解析
1.原式=2×10^2005-1+(10^2005-1)^2=2×10^2005-1+(10^2005)^2-2×10^2005+1=(10^2005)^2=10^4010
2.3.6×31.4+(31.4+12.5)×6.4=3.6×31.4+6.4×31.4+12.5×0.8×8=(3.6+6.4)×31.4+80=314+80=394
3.412×0.81+11×9.25+(412+125)×0.19=412×0.81+412×0.19+125×0.19+0.11×(800+125)=(0.81+0.19)×412+88+125×(0.11+0.19)=412+88+37.5=537.5
4.88...88(2010个)×99...99(2010个)+33...33(2010个)×3×11...11(2009个)=88...88(2010个)×99...99(2010个)+99...99(2010个)×11...112(2009个1)=(10^2011-1)×(88...88(2010个)+11...112(2009个1))=(10^2011-1)×10^2010
5.⑴部分展开得(0.23+0.34+0.65)+(0.23+0.34)×(0.23+0.34+0.65)-(0.23+0.34)-(0.23+0.34+0.65)×(0.23+0.34)=0.65
⑵=0.01+0.02+...+0.09+0.1+0.2+...+0.9+1+2+...+9+10+20+...+90=(0.01+0.1+1+10)×(1+2+...+9)=11.11×10×9÷2=499.95
6.原式化为[(35.16×1/4+38.42/2)×1/5-(1.63+2.36)]×4=35.16×1/4×1/5×4+38.42/2×1/5×4-(4-0.01)×4=35.16×1/5+38.42×2×1/5-16+0.04=112×1/5-16+0.04=6.44
7.原式=(100+300+500+700+900)+24.68×5=2500+123.4=2623.4
8.原式=(0.1+0.3+0.5+0.7+0.9)+(0.11+0.13+…+0.99)=0.1×(1+3+…+9)+0.01×(11+13+…+99)=0.1×(1+9)×5÷2+0.01×(11+99)×45÷2=27.25
Ps:郁啊,敲数学进电脑麻烦死了!