1. "Hua Cup" is a national large-scale youth mathematics competition to commemorate and learn from Professor Hua, an outstanding mathematician in China. Professor Hua was born in 19 10, and now "Hua Cup" stands for double digits. It is known that the sum of 19 10 and "Huabei" is equal to 2000.
2. When the length of each side of a rectangle increases by 10%, what percentage does its perimeter and area increase respectively?
3. The picture in the title is the surface expansion of a cube. If you fill in numbers on each side of the cube so that the sum of the two numbers on the opposite side is 7, what are the numbers in A, B and C?
4. In a list of numbers:, 1 and the difference between each number is smaller than which number?
The manned spacecraft "Shenzhou 5" returned to Earth from space at 6: 05 am on June 16, 2003, and realized the Chinese dream of flying. The spacecraft circled the earth 14 times, of which the last 10 circle was along a circle 343 kilometers above the ground.
6. As shown in the figure, a circular piece of paper is divided into four identical sectors, each of which is covered with red and yellow respectively. How many different paintings are there?
7. At some time between 9 o'clock and 10, the minute hand position five minutes ago is the same as the hour hand position five minutes later. Q: What time is 9 o'clock?
8. There are 54 cards in a deck. How many cards must be drawn to make at least two of them have the same number of points?
9. Write a two-digit number at will and repeat it three times in turn to form an eight-digit number. Divide the quotient obtained by dividing this eight-digit number by this two-digit number by 9. Q: What is the remainder?
10. A rectangular wooden board with a length of 90 cm and a width of 40 cm was sawed into two pieces and then put together to form a square. Can you do it?
1 1. As shown in the figure, the diameters of two semicircles are on the same straight line, the chord AB is tangent to the small circle and parallel to the diameter, and the chord AB is 12 cm long. Find the area of the shaded part in the figure (pi = 3. 14).
12. A small iron ring with a radius of 25 cm rolls along the inside of a large iron ring with a radius of 50 cm without sliding. The small hoop rolls around the big hoop and returns to its original position. How many times does the small hoop turn by itself?
answer
1.94
Solution: From ○+"cup" =4, we know that "cup" stands for 4 (no carry addition); Then 19 1+ "Hua" =200, knowing that "Hua" stands for 9. So the two-digit number represented by "Huabei" is 94.
2. The perimeter increased by 10% and the area increased by 2 1%.
Solution: If the length of a rectangle is A and the width is B, then the perimeter and area of the original rectangle are ab.
Therefore, when the length of each side is increased by 10%, the perimeter is increased by 2 (1.1a+1b)-2 (a+b) = 2 (a+b) ×/kloc-.
The area increased by1.1a×1.1b-ab =1.21b-ab = ab× 2 1%, that is, the area increased by 2/kloc-0.
3.a—6； b-5； Carbon -3
Solution: 1, 4, A and C are the faces of B, 2 is the opposite of B, and B needs to fill in 5; 1, 2, b, a is the face of c, 4 is the opposite of c, and c should be filled with 3; 1 is the antonym of a, and a should be filled with 6.
4. From the beginning
Solution: The characteristic of this column number is that the denominator of each number is 2 larger than the numerator, and the numerator is an odd column. The solution needs 1- 999.5, starting from n = 1000, and the conditions are met.
5.42 1639.2 km.
Solution: 2× 3.14× (6371+343 )×10 = 421639.2km.
6.6 species. Draw each sector counterclockwise:
Red, red, red, red, yellow, red, yellow and yellow.
Red, yellow, red, yellow, yellow, yellow, yellow, yellow.
7.9: 55
Solution: Because the minute hand walks 6 degrees per minute, 30 degrees in 5 minutes, 0.5 degrees per minute and 2.5 degrees in 5 minutes, the angle between the minute hand and the hour hand is 30+2.5 = 32.5 degrees, and the minute hand walks 6-0.5 = 5.5 degrees more than the hour hand. From 9 o'clock to now, the minute hand has gone 270 degrees more than the hour hand.
8. 16 sheets
Solution: excluding Wang and Xiao, only 14 is needed for each suit 13, plus Wang and Xiao, 16 is needed.
9. Four
Solution: No matter what two digits are written, the number of eight digits divided by two digits is1010101,1010/÷.
10. Yes. Because the side length of a square is 60 cm, you can spell it like this:
1 1.56.52 cm2
Solution: If the small circle is 0, AB is the diameter of the big circle, and the shadow part is half of the big circle, then the area of the shadow part is: = = 56.52 (square centimeter).
12. 1 circle
Solution: Because the radius of the small iron ring is half that of the big iron ring, the circumference of the big iron ring is twice that of the small iron ring, that is, the small iron ring rotates twice along the big iron ring and returns to its original position. Where 1 circle belongs to the revolution of the small ring, and the other circle is the rotation of the small ring itself. So the small ring itself rotates 1 turn.
It can also be understood that at first, at point A on the small ring, we observed the radius OA, as shown in figure (1). When the small ring rolls along the inner wall of the big ring to the position opposite to the initial position, as shown in Figure (2), the radius o a also moves to the position opposite to the initial position. At this time, OA has only walked half a circle along the inner wall of the big ring. After the second half of the circle, OA coincides with the initial position, at which time OA itself turns to 65438.
/NewsList- 14 1.aspx
Can you surf the Internet? There is a website.
Honey, I don't want extra points. I just want to adopt. Thank you.