五年级奥数___分数的拆分

五年级奥数___分数的拆分
五年级奥数___分数的拆分

分数的拆分

专题分析:

在英国伦敦的博物馆中,陈列着十九世纪苏格兰考古学家兰特在埃及发现的纸草书,后人称之为兰特纸草书。在兰特纸草书上,人们发现了独特的埃及分数,这些分子为1的分数用不同的象形文字记载着很多历史古题。比如7/8=1/2+1/4+1/8,有人按兰特纸草书的记载这样解释:把7个面包平均分给8个人,不但每个人分的数量一样多,而且每人分的块数也一样多。可以这样分,把其中四个面包每个切成两等份,把另两个面包每个切成四等份,最后一个切成八等份,每人拿大、中、小面包各一份。这有多妙啊!下面我们就研究一些类似的问题。例1:把11根糖棒平均分给12个人,每根糖棒同样长,分时一次只能切一根,且要平均分。问:最少要切几刀?

例2:在1/6=1/()+1/()的括号中填入不同的整数使等式成立。

例3:将2/3拆分成两个不同单位分数之和的形式。

例4:在1/()+1/()+1/()+1/()+1/()+1/()=1的括号中填入互不相同的自然数,使等式成立。

例5:计算

111111

... 1223344519202021 ++++++

??????

例6:计算

11111 144771********* ++++

?????

例7:计算

234100...1(12)(12)(123)(123)(1234)(12...99)(12...100)

++++?++?++++?++++++?+++

例8:计算:1111...12123123 (10)

+++++++++++。

练习:

1、求出下列各分数所有形如

11a b

+的表达式,其中a 、b 为不等的整数: 15 111 14 116

2、求出17、110、112所有形如11a b -的表达式,其中a 、b 为不等的整数。

3、计算3276912920730341754942870130208304418550

+++++++。

4、计算2×4+4×6+6×8+…+18×20+20×22+22×24。

5、计算

1111 1234 (20)

61220420

+++++。

6、A、B、C是三个互不相同的自然数,并且满足:1115

6

A B C

++=,求A B C

++。

7、从下面的分数中找出10个来,使它们的和为1(不许重复):

1,1

2

1

3

1

4

1

5

,……

奥数小测验

1.有三个自然数,它们相加或相乘,都得到相同的结果,这三个数中最大的是。

2.四个人年龄之和是77 岁。最小的10 岁,他与最大的年龄之和比另外二人年龄之和大7 岁,最大的年龄是岁。

3.把被减数、减数、差相加得40,被减数是。

4.有一幢楼房高17 层,相邻两层间都有17 个台阶。某人从一层走到十一层,一共要登个台阶。

5.有100 位旅客,其中有10 人既不懂英语,又不懂俄语,有75 人懂英语,83 人懂俄语,既懂英语又懂俄语的有人。

6.有一块三角形地,三条边分别为120 米、150 米、80 米,每10 米种一棵树,三条边上共种树棵。

7.从401 到1000 的所有整数中,被8 除余数为1 的数有个。

8.用一个自然数与它自己相减、相加、相除所得的差、和、商三个数加起来恰好等于101,这个自然数是。

9.四三班上操正好排成人数相等的三行,小明排在中间一行,从前从后数都是第八个,全班有学生人。

10.把数字5 写到一个三位数的左边,再把得到的四位数加上400,这时,他们的和是这个三位数的55 倍,这个三位数是。

Class: Name:

( )1. Good morning! !

A.Morning !

B.Hello !

C.Hi !

( )2. Nice to see you again ! .

A.How are you ?

B.Nice to see you , too .

C.How do you do ?

( )3.Good night,mom !

A.Night !

B.Good night !

C.Good evening .

( )4.How do you do ?

A.How are you ?

B.Fine,thanks .

C.How do you do ?

( )5.How many story books do you have ?

A.I have 10.

B.I can see 10.

C.Thirty yuan.

( )6.Do you have new teachers?

A.Yes,we do .

B.Yes,we don’t.

C.Yes,we have .

( )7.Who’s your art teacher ?

A.Mr Zhu.

B.Miss Zhu.

C.He’s tall.

( )8.What’s he like?

A.He’s tall and strong .

B.Yes,he is.

C.Mr Zhu.

( )9.Is your English teacher young?

A.No,she isn’t.

B.Yes,she is .

C.No,she is.

( )10. ? Her name is Chen Jie.

A.What’s your name ?

B.What’s she name ?

C.What’s her name ?

( )11. ? I like Chinese,math and English.

A.What classes do you like?

B.What do you like?

C.What are you like ? ( )12. ? We have English and P.E.

A.What do you have on Mondays ?

B.What do you have ?

C.What do you have on Monday?

( )13. ? It’s Monday.

A.What is it today ?

B.What day is it today ?

C.What day is today ?

( )14. ? I watch TV and do my homework.

A.What do you do ?

B.What do you do in Mondays?

C.What do you do on Sundays ?

( )15.May I have a look ?

A.Sure.Here you are .

B.Look !

C.Here you are .

( )16.Our math teacher is Canada.

A.from

B.in

C.at

( )17.I three new teachers.

A.has

B.am

C.have

( )18.What’s Chinese teacher like ?

A.you

B.your

C.you’re

( )19.My P.E.teacher is thin.

A.too

B.so

C.very

( )20.There are days in a week.

A.six

B.seven

C.eight

( )21.There are month(月)in a year(年).

A.ten

B.eleven

C.twelve

( )22.I often watch TV Saturday .

A.on

B.in

C.at

( )23.I like P.E. I don’t lime music.

A.but

B.and

C.so

( )24.This is apple. It is red apple.

A.a , a

B.an,an

C.an, a

( )25.What do you like ?

A.classes

B.class

C.class’s

六年级英语测试题

Class: Name:

( )1. How are you ?

A.Fine,thanks.

B.Yes,it is.

C.How are you ?

( )2. Nice to meet you !

A.Fine,thank you.

B.OK.

C.Nice to meet you ,too !

( )3. How do you go to school ?

A.I go to Canada by plane.

B.I go to school by bike.

C.What about you ?

( )4. How do you go to the USA ?

A.I usually go to school by bus.

B.I go to England by ship.

C.I go by plane.

( )5. ? My home is near the post office.

A. Where is your home ?

B.OK.

C.See you then!

( )6. See you at 2 o’clock.

A.See you then !

B.The fifth floor.

C.It’s easy.

( )7. ? You can go by the No.15 bus.

A.It’s not far.

B. How can I get to Zhongshan Park ?

C.Sure.

( )8. Where is the hospital?

A.Next to the cinema.

B.Thank you .

C.You’re welcome.

( )9. Excuse me ,is there a cinema near here ?

A.Yes,there is .

B.No,it’s not far.

C.It’s near the post office.

( )10.? ? It’s near the post office.

A.Yes,there is .

B.No,it’s not far.

C. Where is the library?

( )11. ? It’s next to the hospital.

A. Where is the cinema ,please ?

B.Is it far ?

C.Go straight.

( )12. How can I get to the hospital ?

A.It’s next to the hospital.

B.You can go by the No.201 bus.

C.Thank you.

( )13.Thank you .

A.Thank you .

B.OK.

C.You’re welcome.

( )14. How can I get to the museum?

A.Go straight.Then turn left.

B.Thank you .

C.It’s east of the cinema .

( )15. Where is the post office ?

A.Go straight.Then turn left.

B.Thank you .

C.It’s east of the cinema .

( )16. What are you going to do this evening ?

A.I’m going to the cinema .

B.I go to school on foot.

C.Yes,it is.

( )17. Is it far ?

A.No,it is .

B.Yes , it is .

C.Yes,it isn’t. ( )18. do you go to school ?

A.What

B.Where

C.How

( )19. I go to school bike.

A.on

B. by

C.get

( )20. Can I go foot ?

A.by

B.at

C.on

( )21.How can I to the post office ?

A.near

B. get

C.for

( )22. me.

A. Excuse

B. How

C.next

( )23. birthday to you !

A. After

B.Happy

C.First

( )24. The hospital is the left.

A. at

B.in

C.on

( )25. is the bookstore ?

A.Where

B.How

C.When

四年级英语测试题

Class: Name:

( )1.Good afternoon !

A.Hello!

B.Hi !

C.Afternoon !

( )2.Nice to see you again !

A.How are you ?

B.Hello !

C.Nice to see you , too.

( )3.Good night,moom !

A.Good evening !

B.Good night !

C.Night !

( )4.How are you ?

A.Fine,thank you .

B.I am 10.

C.Nine .

( )5.How do you do ?

A.Fine ,Thank you .

B.How are you ?

C.How do you do ?

( )6.How old are you ?

A.How are you ?

B.I am 11.

C.I have 11.

( )7. ? I have 23.

A.How many books do you have ?

B.How many books can you see?

C.How many book do you have ?

( )8. ? I can see 6.

A.How many lights do you have ?

B.How many lights can you see ?

C.How many light can you see ?

( )9.May I have a look ?

A.Sure.Here you are .

B.Look!

C.Sure.Here are you .

( )10. ? 50 yuan.

A.How much is this schoolbag ?

B.How many is this schoolbag ?

C.How much are this schoolbag ?

( )11.Where’s my seat ?

A.It’s near the door.

B.It’s on the door.

C.It’s under the door. ( )12.Let’s clean the desks and chairs.

A.All right !

B.Hello !

C.It’s nice .

( )13.What’s this ?

A.There is a board .

B.It’s a bee.

C.It’s bee.

( )14. ? My name is Mike.

A.Here are you ?

B.What’s your name ?

C.How do you do ? ( )15.Who’s the inventor of paper ?

A.Chinese people.

B.Oh! Great !

C.Hello!

( )16.I a student. You a teacher.

A.am ,am

B.are, are

C.am, are

( )17.This a boy.His name Zhang Peng.

A.is, is

B.am , is

C.is , are

( )18.Let clean the fish bowl.

A.I

B. me

C.my

( )19.This is apple.It is red apple .

A.an ,an

B.a, a

C.an, a

( )20.We a new classroom.

A.are

B.have

C.has

( )21.There a bee in our classroom.

A. is

B.are

C.am

( )22. have a new schoolbag. schoolbag is heavy.

A.I , my

B.I ,My

C.My , I

( )23.Put your English book your head.

A.at

B.in

C.on

( )24.There many books in the desk.

A.am

B.is

C.are

( )25.How many do you have ? A.pencil B.pencils C.pencils. 三年级英语测试题

Class: Name:

( )1.当向别人打招呼时,应该说:

A.Hello.

B.Good morning .

( )2.How are you ? 的正确答语是:

https://www.360docs.net/doc/869482865.html,

B.I’m fine,thank you .

( )3.当想知道别人的名字时,应该说: A.What’s your name ? B.See you. ( )4.字母K的小写是:

A.k

B.

( )5.Nice to meet you 的意思是:

A.见到你很高兴。

B.你好吗?

( )6.向别人告别时,应该说:

A.Good bye!

B.Hi.

( )7.Jenny is a

A.boy

B.girl

( )8.Li Ming is a

A.boy

B.girl

( )9.Jenny lives in

A.Canada.

B.China.

( )10.字母P的大写是:

A.P

B.q

( )11.当向别人说谢谢时,应该说:

A.Nice to meet you .

B.See you later.

( )12.早上好的正确答语是:

A.Good morning .

B.See you later.’( )13.What’s this ?It’s a

A.desk

B.book

( )14.This is a

A.teacher

B.Danny

( )15.This is a boy.What’s name ?

A.his

B.her

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