学而思奥数天天练栏目每日精选一套中等难度的试题，各年级分开，配有详细答案及试题解析，适合一些有过思维基础训练、考题学习经历，并且奥数成绩中上的学生。

A set of moderately difficult questions is selected daily from the training column for several days. Each grade is separated. It is equipped with detailed answers and test questions analysis. It is suitable for students who have had basic thinking training and test questions learning experience, and have achieved high scores in the Olympics.

学而思奥数天天练栏目每日精选一套高等难度的试题，各年级分开，配有详细答案及试题解析，此类试题立足于杯赛真题、综合应用和加深各知识点，适合一些志在竞赛中夺取佳绩的学生。

A series of high-level questions are selected every day for the days of practice. Each grade is separated, with detailed answers and analysis of the questions. These questions are based on the true questions of the cup competition, comprehensive application and deepening of the points of knowledge. They are suitable for students who want to achieve good results in the competition.

·本试题由上海学而思奥数全职教师曹天一老师精选、解析，以保证试题质量

This paper is selected and analyzed by Professor Cao Tianyi, a full-time teacher from Shanghai University and Siao Number, to ensure the quality of the test paper.

名师介绍：

Famous teacher introduction:

华东理工大学化学工艺专业硕士，在小学和初中连续学习了4年奥数，曾获得黑龙江省树人杯奥数省一等奖（六年级组）、凭借优异的成绩跳过小学六年级直接升入初中、全国初二数学竞赛省二等奖，初二物理竞赛省一等奖，初二英语竞赛省三等奖，初三化学竞赛省二等奖，拜耳—华东杯化工原理大奖赛三等奖，在小学五年级凭借优异的成绩直升市重点初中，之后考入省重点高中，对奥数方面的内容了如指掌。

Master of Chemical Technology, East China University of Science and Technology, has studied for four consecutive years in primary and junior high schools, won the first prize (sixth grade group) of the Heilongjiang Shuren Cup Olympic Mathematics Province, skipped the sixth grade of elementary school with outstanding results, and was directly promoted to the second prize of the junior middle school and the second prize of the provincial mathematics competition of the whole country. Second English Competition Provincial Third Prize, Third Junior Chemistry Competition Provincial Second Prize, Bayer-East China Cup Chemical Principles Grand Prix third prize, in the fifth grade of primary school with outstanding results to the municipal key junior high school, and then admitted to the provincial key high school, the contents of the Olympic Mathematics like the palm.

教学特色：

Teaching features:

善于集中学生的注意力，突出重点，有时也很幽默，善于调节课堂气氛，课堂气氛即严谨又轻松。

Good at focusing students'attention, highlighting key points, and sometimes humorous, good at adjusting the classroom atmosphere, the classroom atmosphere is rigorous and relaxed.

对学生来说曹老师绝对是你的良师益友，对解答学生问题方面非常有耐心。

Teacher Cao is absolutely your good teacher and friend to the students. He is very patient in answering students'questions.

座右铭

Motto

学习改变命运查看曹天一老师介绍

Learn to change fate, see teacher Cao Tianyi.

·每道题的答题时间不应超过15分钟

The answer time for each question should not exceed 15 minutes.

·您可以按“下载适合打印版本试卷”获得word版本试卷进行打印。

You can print the word version of the test paper by downloading the printed version of the test paper.

小学一年级奥数天天练：赛跑

The first year of primary school Olympiad daily training: Race

小动物们举行动物运动会，在长跑比赛中有4只动物跑在小松鼠的前面，有3只动物跑在小松鼠的后面，一共有几只动物参加长跑比赛？

At the animal games, four animals ran in front of the squirrel, three animals ran behind the squirrel. How many animals took part in the long-distance race?

小学二年级奥数天天练：擦桌子

Elementary school grade two Olympiad daily practice: wipe the table

小刚是卫生小组长，他带领12个同学一起擦教室里的40张课桌，平均每人擦多少张课桌，余下的药小刚自己擦，那么小刚至少擦多少张桌子才能完成任务？

Xiao Gang is the head of the health team. He leads 12 students to clean 40 desks in the classroom. How many desks do he clean on average, and the rest of the medicine Xiao Gang wipes himself. So how many desks can Xiao Gang wipe at least?

小学三年级奥数天天练：人数

Number three in primary school, Olympiad daily practice: number

有50名学生参加联欢会，第一个到会的女生同全部男生握过手，第二个到会的女生只差1个男生没握过手，第三个到会的女生只差两个男生没有握过手……这样最后一个女生与7个男生握过后，那么50名学生中，男生有几名？

Fifty students attended the party. The first girl shook hands with all the boys. The second girl only missed one boy who didn't shake hands. The third girl only missed two boys who didn't shake hands. So when the last girl and 7 boys shook hands, how many boys were there among the 50 students?

小学四年级奥数天天练：求面积

Primary school grade four Olympiad daily training: Area

右图中每个小平行四边形的面积是1个面积单位,求阴影部分的面积.

The area of each small parallelogram in the right picture is the 1 area unit, and the area of the shadow part is calculated.

天天练

Practice every day

小学五年级奥数天天练：求数

Elementary school grade five Olympiad daily training: ask for number

有一个三位数是8的倍数，把它的各位数字的顺序颠倒过来所得到的新三位数与原三位数的和恰好是1111.那么原来的三位数是多少？

One of the three digits is a multiple of eight, and the sum of the new three digits and the original three digits is 1111. So what is the original three digits?

小学六年级奥数天天练：时间

Elementary school grade six Olympiad daily practice: time

李叔叔下午要到工厂上3点的班，他估计快到上班的时间了，就到屋里去看钟，可是钟停在了12点10分。他赶快给钟上足发条，匆忙中忘了对表就上班去了，到工厂一看离上班时间还有10分钟。夜里11点下班，李叔叔回到家一看，钟才9点钟。如果李叔叔上、下班路上用的时间相同，那么他家的钟停了多长时间？

Uncle Li is going to work at 3 o'clock in the afternoon in the factory. He estimates that it is almost time to go to work. He goes to the room to look at the clock, but the clock stops at 12:10. He quickly wound up the clock, forgot to check his watch in a hurry, and went to work, 10 minutes to the factory. At 11 o'clock at night, Uncle Li went home and saw that the clock was 9 o'clock. If Uncle Li spends the same amount of time on his way to and from work, how long does his clock stop?

----------------------------------------------------------------------------

----------------------------------------------------------------------------

一年级答案：

First grade answer:

解答：这道题要明确问题的关键，我们可以把跑步的所有小动物看成一个队列，小松鼠前面有4只小动物，后面有3只小动物，在这个队列中，就是没有数松鼠自己，所以求这队的总数还要把小松鼠加上。4+3+1=8（只），一共有8只动物参加长跑比赛。

Answer: To clarify the key to this problem, we can think of all the small animals running as a queue. There are four small animals in front of the squirrels and three small animals behind them. In this queue, there are no squirrels themselves, so we ask the total number of the squirrels in this queue to be added. 4+3+1=8 (only), a total of 8 animals participate in the long-distance race.

二年级答案：

Answer in Grade Two:

解答：这道题要求平均每人擦多少张课桌要用除法计算。不过应该有13个同学在劳动。4013=3（张）……1（张）3+1=4（张）所以小刚至少擦4张桌子

Answer: how many tables per person is required for this question? But there should be 13 students working. 4013=3 (Zhang)... 1 (Zhang) 3+1=4 (Zhang), so Xiao Gang wiped at least 4 tables.

三年级答案：

Answer in Grade Three:

解答：设有a名女生, b名男生.根据题意,第a个到会女生的序号与同她握过手的男生有一定关系,可得下表：

Answer: There are a female student and a male student. According to the meaning of the question, the serial number of the first female student to attend the meeting is related to the boy who shook hands with her. The following table can be obtained:

天天练

Practice every day

因为最后一名女生与7名男生握过手,所以b - a +1=7,也就是 b – a =6,于是男生:(50+6)÷2=28(人)。

Because the last girl shook hands with seven boys, so b-a+1 = 7, that is, B-A = 6, so boys: (50 + 6) 2 = 28 (people).

四年级答案：

Answer in Grade Four:

解答：本题用毕克定理，S=N+L÷2-1 图形内部格点数为16,图形周界上格点数为7. 图形的面积为: 16+72-1=18.5(面积单位)

Answer: This problem uses Bike's theorem, S = N + L_2-1 graph interior lattice number 16, graph perimeter lattice number 7. Graphic area is: 16 + 72-1 = 18.5 (area unit)

五年级答案：

Answer in Grade Five:

解答：设原三位数为abc，则新三位数为cba，根据位置原理有，abc+cba=101(a+c)+20b.

Answer: Let the original three digits be abc, then the new three digits be cba. According to the position principle, ABC + CBA = 101 (a + c) + 20b.

又因为1111=101×11，且b为一位数，所以a+c=11,b=0;原数为8的倍数，则c=4,a=7,所以原来的三位数是704.

And because 1111 = 101 *11 and B is a single digit, a + C = 11, B = 0; if the prime number is a multiple of 8, then C = 4, a = 7, the original three digits are 704.

六年级答案：

Answer in Grade Six:

解答：这道题看起来很“乱”，但我们透过钟面显示的时刻，计算出实际经过的时间，问题就清楚了。钟从12点10分到9点共经过8时50分，这期间李叔叔上了8时的班，再减去早到的10分钟，李叔叔上、下班路上共用8时50分－8时－10分＝40（分）。李叔叔到工厂时是2点50分，上班路上用了20分钟，所以出发时

Answer: This question looks "confusing", but when we calculate the actual time elapsed through the clock, the question becomes clear. The clock went through 8:50 from 12:10 to 9:00, during which Uncle Li went to work at 8:00 and subtracted 10 minutes of early arrival. Uncle Li shared 8:50-8:00-10 = 40 on his way to and from work. Uncle Li arrived at the factory at 2:50, and spent 20 minutes on his way to work.