Mathematics diary about 300 words in Grade Four

Today, my mother and I went shopping in the supermarket. The supermarket was full of people and goods. My mother quickly took me to buy what the buyer needed. We first bought a watermelon. The watermelon was 3 yuan per kilo and weighed 4 jin. Then we came to the place where the meat was sold. The meat was 8 yuan per kilo and we bought 3 jin. Later, we bought a box of milk

RELATED INFORMATIONS

1. This is a question about comparison The length ratio of the three sides of a triangle is 3:4:5. The shortest side is 3 cm. What is the longest side of the triangle?
2. The formula of cylinder volume The formula of volume and area of cylinder and cone
3. Unified deformation formula How to calculate asin α + bsin α = (radical a ^ 2 + B ^ 2) sin (x + α) x
4. Seventh grade mathematics geometry It is known that ∠α and ∠β are mutually complementary, and half of ∠β is 30 ° smaller than ∠α, so ∠α and ∠β can be calculated What about complementarity?
5. Why is the formula for the area of the side of a cone this The formula given in the book is s = π (R '& sup2; + R & sup2; + r'l + RL) I can understand that π R '& sup2; + π R & sup2; is the area of the top and bottom Why is π (r'l + RL)
6. Coordinate formula of parabola vertex Is the vertex coordinates of y = ax & sup2; + BX
7. The formula of parabola vertex ordinate
8. For example: BX + ay = AB (a)
9. Given the slope of two intersecting lines, the formula for calculating the angle between them (how do you get it?)
10. Given the vertex coordinates, the equation of the straight line where the hypotenuse is, and the slope of the straight line where the hypotenuse center line is, calculate the other two coordinates. See below for details Given the vertex C (- 2,3) of a right triangle, the linear equation of the hypotenuse AB is 4x-3y-7 = 0, and the slope of the straight line of the middle line on the hypotenuse is - 4 / 3, the coordinates of point a and B are obtained
11. Mathematical diary about decimal division (about 200 words), mathematical diary about polygon area (about 260 words)
12. Life examples solved with mathematical knowledge The best way to solve life problems with mathematical knowledge is at the level of junior high school,
13. The story of using mathematical knowledge in life Quality and quantity
14. Who has a good way to learn mathematics
15. Write a composition about saving water, use the statistical knowledge learned in math class! In ten minutes,
16. Solving problems by solving equations 1. There are 874 seats in the school auditorium, with a total of 23 rows. Each row has the same number of seats. How many seats are there in each row?
17. A batch of saplings will be planted. If each person plants 10 saplings, the remaining 6 saplings will not be planted. If each person plants 12 saplings, the remaining 6 saplings will be missing. How many people plant trees? List the equations according to the meaning of the question
18. On the pursuit of the equations in the seventh grade
19. In junior high school, the principle of common factor is put forward, 1. Decomposition common factor: 2x (A-2) + 3Y (2-A) 2. The common factor of polynomial A & # 178; - 2Ab + B & # 178;, a & # 178; - B & # 178; is (?) 3. Given X & # 178; + X-1 = 0, find the value of the cubic power of X + 2x & # 178; + 1999
20. Chemical formula and literal expression of carbon dioxide produced by reaction of calcium carbonate and dilute hydrochloric acid?