1, formula

Make up four formulas with 6, 7, 8 and 9, and add two numbers to two numbers with the same number.

Answer: 67+98 =165; 68+97= 165; 76+89= 165; 79+86= 165

2. How much does the dividend increase?

Divide 258 by 25, and if there is no remainder, the dividend should be increased at least ().

Answer: 17

3. Money in the piggy bank

Xiaoming has 38 coins with a face value of 1 yuan in his piggy bank, with 50 cents. If the number of coins of 1 yuan is exchanged with the number of coins of 50 cents, the total value will be reduced by 3 yuan. Ask Xiao Ming how much money he has in his piggy bank.

Answer: 30 yuan.

4. Define a new operation

Define an operation: a △ b = a× b+a-b.

Q: (1) 8 △ 5; ⑵ 10△(5△6)

Answer: 4327 1

5. Be famous on the list

The full score of the exam is 100, and the average score of Xiaoming's three exams is 90. If the average score reaches 94, he will be on the honor roll. Excuse me: How many times does Xiao Ming have to get full marks in a row before he can get on the list?

Answer: 2 times

6. I found that

Uncle Li is going to plant corn on a rectangular land of 360 square meters. If the length of a rectangle is 20 meters, 40 meters, 60 meters and 120 meters, how many meters should it be? Please fill in the form below. What did you find?

Length (m) 20 40 60 120

Width (m)

Answer:18,9,6,3

7. Help Huanhuan

When calculating "20+□× 5", Huanhuan calculates the addition first and then the multiplication, and the result is 500. Can you help him work out the correct figure for this problem?

Answer: 420

8. What is the integer part?

Let a = 0.8+0.88+0.888+...+0.88888, what is the integer part of a?

Answer: 8

9. How many routes can I take?

There are four roads from home to the supermarket, three roads from the supermarket to the food market, and several routes from home to the food market.

Answer: 12

10, where is he?

Honghong walked from A to the east at a speed of 60m/min for 5 minutes, and then walked to the northwest at the same speed for 5 minutes. At this point, he is in position a.

() is () meters away from ().

A: A is 300 meters west of south.

1 1, drawing

According to the following description, draw a tour bus route map: "Happy June 1" good tour bus travels 3 kilometers from the departure station to the zoo in the southeast direction, 4 kilometers to the botanical garden in the northeast direction, and 5 kilometers to the amusement park in the southeast direction.

12. Fill it in.

According to the tour bus route map, how to get back?

From (), drive () km in the direction of () to (), then drive () km in the direction of () to (), and then drive () km in the direction of () to ().

A: The amusement park is 40 5 kilometers northwest, the botanical garden is 30 4 kilometers southwest and the zoo is 20 3 kilometers northwest. The starting point is 13. How many minutes will it take?

13, from home to school, if you ride for 3 minutes first, then walk for 15 minutes; If you walk for 5 minutes first, then you can get there by bike for 5 minutes. So how many minutes does it take to walk from home to school?

Answer: 30

14, simple calculation

1+3+5+…+97+99

Answer: 2500

15, simple calculation

7999+799+79+9

Answer: 8886

16, find the method

First use the counter to calculate the number of the first three questions, and then find out the number of the last two questions that are regularly filled in.

1089×9= 10989×9= 109989×9=

( )×9= 989990 1 109999989×9=( )

Answer:109989,9899901.

17, simple calculation

4300×35+43×6500

Answer: 430,000

18, simple calculation

9999×7778+3333×6666

Answer: 9990000

19, simple calculation

846- 12 1-279- 146

Answer: 300

20, simple calculation

354× 100 100 1

Answer: 354354354

2 1, different methods

25× 12, four different methods are used for simple calculation.

22. Symbolic representation number

What are the numbers represented by □, △ and ○ for the following three addition formulas to hold?

□+□+□+△+△=23

□+□+△+○= 17

○+○+□+△= 15

□=( ) , △=( ) , ○=( ).

Answer: 5, 4, 3

23. Average

The four numbers A, B, C and D are removed one at a time, and the other three numbers are averaged. This is done four times and you get 48, 44, 40, 36. Find the average of four numbers.

Answer: 42

24. How many are there in a * * *?

Use the four numbers 1, 2, 3 and 4, plus the decimal point, to form a decimal without repeating numbers. How many decimal places are there?

Answer: 72

25. Form decimal

Use four "8" s and four "0" s to add decimal points to form decimals.

(1) The largest decimal is ()

The smallest decimal is ()

(3) Only one zero is read, and the smallest decimal is ()

(4) The maximum number of zeros read is ()

The answer is: 8880000.80.000000008001

26, ranking

At the school sports meeting, the results of the 50-meter race are as follows:

Player 1: 9. 1 sec Player 2: 8.6 sec Player 3: 8.5 sec.

Player 4: 9.0 seconds, player 5: 8.4 seconds and player 6: 8.2 seconds.

According to the results, their ranking is:

First place, second place and third place.

Fourth place () fifth place () sixth place ()

Answer: ⑤ ⑤ 324 1

27. How many zeros are there at the end?

How many zeros are there at the end of 99 ...9× 99 ...9+ 199 ...9?

2008, 2008, 2008

We can find the pattern and answer it.

9×9+ 19= 100

99×99+ 199= 10000

999×999+ 1999= 1000000

……

Answer: 40 16

28. How many decimal places are there?

How many decimal places are there that are greater than 1.5 and less than 1.6? Write it out.

Answer: 9, 1.5 1, 1.52... 1.59.

29. What was the initial decimal?

Enlarge a decimal point by 100 times, then move the decimal point three places to the left, then enlarge the decimal point by 100 times, and finally move the decimal point one place to the left. The result is 3.52. Excuse me, what is the initial decimal number?

Answer: 3.52

30. minimax and minimax

The approximate value obtained by rounding three decimal places is 2.0. The maximum value of this three decimal places is () and the minimum value is ().

Answer: 2.049 1.95 1.

3 1, original decimal

7.26 is an approximation of a three-digit decimal. The original smallest decimal is ().

Answer: 7.255

32. The price of chess

The school bought 12 sets of chess, and the total price written on the invoice was 42. 1□ yuan (the number in □ is illegible). Do you know the price of each chess set?

Answer: 3.5 1 yuan.

33, the longest and shortest

The three sides of a triangle are all full centimeters in length, and two of them are 5 centimeters and 7 centimeters respectively. What is the longest length of the third side? How many centimeters is the shortest?

Answer: 1 1, 1.

34, isosceles triangle

An isosceles triangle with two sides of 3 cm and 6 cm, and a base angle of 76.

(1) How long is the third side of this triangle?

What is the vertex angle of this triangle?

Answer: 6 cm, 28.

35, simple calculation

999.9+99.9+9.9+0.9=

Answer: 1 1 10.6.

36, group number summation

Three numbers, 3,2 and 1, are used to form different two-digit decimals. What is the sum of these two decimal places?

Answer: 13.32

37. Who can win?

Zhang Ming and Li Hong race in a time limit of 10 second. Whoever runs the long-distance race will win. Zhang Ming ran 1 m in the first second, and then ran 0. 1 m more than the previous second. Li Hong's speed is constant, always 1.5 meters per second. Who can win?

Answer: Li Hong

38. Coins in the piggy bank

Xiaoming's piggy bank contains a number of coins of 50 cents and 1 yuan, with a total value of 25 yuan, of which the number of 50 cents is three times that of 1 yuan. How many 50-cent and 1 yuan coins are there in the piggy bank?

Answer: 30 yuan and 50 cents, 1 yuan 10 yuan.

39, the last number

The last digit of the sum of 13 127.06 is ().

Answer: 8

40, series

There is a column number: 5, 6, 2, 5, 5, 6, 2, 5. ...

The number (1) 125 is ();

(2) The sum of this 125 number is ().

Answer: 5563

4 1, what is the approximate distance?

The taxi pricing standard of a city is: 7 yuan within 3km, and every kilometer 1.2 yuan beyond 3km. Cong Cong paid 9.40 yuan by taxi. How many kilometers did he drive?

Answer: 5 kilometers

42. Reload poplars

Along one side of a canal, from one end to the other, a willow was planted every 10 meter, and a certain * * * planted 15 tree. If we plant one poplar every 7 meters, one * * *, how many poplars should we plant?

Answer: 2 1

43. Flowers between trees

The road in front of the park gate is 80 meters long. Poplars should be planted on both sides of the road, and every two trees should be separated by 8 meters (both ends should also be planted). There should be five more winter jasmine plants between every two adjacent trees. How many seedlings and plants should gardeners prepare for winter jasmine?

Answer: 1 1, 50

44, maximum and minimum

Rectangular table, two people can sit on the long side and 1 person on the wide side. Now, arrange five such tables in a row. (1) How many people can sit in a row? A * * *, how many people can sit? (2) How to sit in a row is the least. How many people can sit in a row?

A: (1) 22 2 14

45. Go to school by bike

It takes Mr. Zhang 20 minutes to get to school by bike in the morning. On the road, there is a billboard every 50 meters. It took Mr. Zhang 2 minutes from the 1 billboard to the 1 1 billboard. How far is teacher Zhang from home to school? How many kilometers?

Answer: 5 kilometers

46, the calculation in the mall

Buying a TV set is more expensive than buying a washing machine in home appliance stores 1250 yuan. Cameras are cheaper than televisions. 520 yuan, a camera uses more 480 yuan than a camera. So how much is the camera more expensive than the washing machine?

Answer: 12 10 yuan.

47. How many pairs of shoes does each person have?

The department store shipped 300 pairs of sports shoes, which were packed in 2 wooden cases and 6 cartons respectively. If there are as many sneakers in two cartons as 1 wooden box, think about it: how many pairs of sneakers are there in each wooden box and each carton?

Answer: 60 pairs of wooden cases and 30 pairs of cartons;

48. Time recorded

The factory conducted an experiment on the new product and recorded it every 3 hours. The first recording was at 9 am. Ask; When was the record of 12?

Answer: 6 pm

49. How many parts does a * * * have?

Uncle Li must finish a batch of parts. On the first day, he made this batch of parts, and the next day, 16 was left. How many parts are there in this batch?

Answer: 80

50. Can you work out the result quickly?

2 1+22+23+……+38+39=30+ 19=

7999+799+79=

2488-(336+488+664)=

8888×667+4444×666=

77×44+77×2 1+23×65=

5200÷(52×4)÷25=

Answer: 570,8877, 1 000,888,000,6500,1.