1, number classification

There are twenty cards on the desk. The twenty numbers are 1, 2, 3... 19, and 20 are written on these cards respectively. Please classify these twenty figures.

2. On the day of the meeting

Xiaoming has a haircut every 30 days, and Xiaogang has a haircut every 40 days. On June 65438+ 10/day, 2000, they went to the barber shop at the same time. When did they meet again in the barber shop this year?

3. Exposure angle

There is an isosceles triangle. This isosceles triangle has two corners covered, revealing an angle greater than 40 and less than 50. Guess, what kind of triangle is this triangle by angle?

4. Block grouping

In math class, the teacher took out some building blocks for Xiaoling in a box with 100 building blocks, and Xiaoling divided them into several groups. If each group has 3 blocks, the result is 1 block left; Five dollars for each group, and there is one left. How much did the teacher give Xiaoling?

5. Use your mobile phone skillfully

There are two ways to charge for the use of Unicom's mobile phone: (1) the monthly rental fee is 40 yuan, and 1 minute call fee is 0.36 yuan. (2) No monthly fee, 0.56 yuan per minute. Which billing method do you think is better?

Think about it: Li Jun, Zhang Ming, Lu Qiang and wang hong took part in the 100-meter race and shot put, with the following results. Who has the best sports performance when the two tests are combined? what do you think?

Li Jun, Zhang Minglu and Wang Qianghong

100 meter run17seconds15s16s19seconds.

The shot put is 6m, 4m, 9m and 7m.

There are several possibilities.

The holiday is coming. Teacher Li and the students in Class 6 (2) discuss such a question: If there is something urgent to inform everyone during the holiday, how to inform the 36 students in the class quickly? If the notification method is a call and each call takes 1 minute, please design a method to save time.

2. Find the number skillfully. A book has 320 pages and is numbered. 1, 2, 3, 4 ... How many numbers do you need?

3. The typesetting workshop needs 2925 numbers to arrange the page number of a book. Please calculate the page number of this book.

4, the size of the possibility.

(1) Please use "may", "may not", "may" and "may not" to talk about the following things.

A. the weather tomorrow

B. toss a coin

C. Close your eyes and find a card in a deck of playing cards.

(2) judge the size of the possibility

A. There are 1 white balls and 9 red balls in a bag, all of the same size.

Close your eyes and touch one. The ball you touch is white.

Is the ball more likely or the red ball more likely?

B There are 100 bulbs, two of which are defective. Take out any one, and this light bulb is it.

Is it more likely to be genuine or defective? Why?

1. There is a batch of 8-meter-long steel bars in the warehouse. Now it is necessary to cut out 40 3-meter-long blanks and 40 2-meter-long blanks, and try to design the most material-saving blanking scheme. How many raw materials do you want?

2. Steel bars with a length of 4 1 cm should be cut into blanks with three lengths of 3 cm, 5 cm and 7 cm, and each blank should have at least 1 piece, and there is no surplus material. How many cutting methods are there? How to cut?

3. It takes 8 minutes for Xiao Ming to get up in the morning, wash his face, brush his teeth and fold the quilt, 6 minutes for doing eye exercises, 2 minutes for washing cups and taking milk powder, and 15 minutes for boiling water. Please arrange the order of doing these things so that Xiao Mingcan can can drink milk as soon as possible. It only takes a few minutes.

4. Mom 1 min boils the kettle, 1 min boils the water, 1 min washes the teapot,1min washes the teacups, and takes tea for 2 min. Xiao Ming estimates that it will take 20 minutes to finish these tasks. How many minutes can you make tea according to your most reasonable arrangement in order to let the guests have tea early?

During the holiday, Xiaoli and her mother learned to cook fish together. She did the following things methodically: wash the fish, cut ginger slices, wash the pot, cook the pot, fry the fish for 2 minutes, 1 minute, 2 minutes, 1 minute, 1 minute,1minute. How many minutes does it take Xiao Li to cook this fish?

7. Zhao Xiangchang went to the village to convene a meeting of village cadres from four villages, A, B, C and D, which are 5 kilometers apart from each other (as shown in the picture). The number of people attending the meeting is 8 in Village A, 5 in Village B, 3 in Village C and 7 in Ding Cun. Ask Zhao Xiangchang in which village to hold the meeting, so that the sum of the distances taken by all the people attending the meeting is the smallest.

5 km, 5 km, 5 km

Ding Cun, Bingcun Village, No.1 Village, Jia Cun

8. Several computers of the same model were produced in Beijing and Shanghai respectively. In addition to local applications, Beijing can support 65,438+00 foreign computers and Shanghai can support 4 foreign computers. It is now decided to give 8 sets to Chongqing and 6 sets to Hankou. If the freight of each computer is shown in the following table (unit: yuan), how to transport it to save the most important freight?

The end of each station

transportation charge

The starting point is Hankou and Chongqing

Beijing 40 80

Shanghai 30 50