Write an essay with two raccoons and crocodiles in 300 words

Crocodile and small bai squirrel.

One day, two little squirrels in the DU forest fell into.

Zhi Xiaohe, they shouted for help. At this time, the crocodile could hear it, and immediately rushed to them, and said to them, "Ride on my back!"

I will take you ashore. "When the little squirrel got on Coco's back, Coco took them ashore. The little squirrel thanked Coco and went home.

Coco, the little crocodile, looked at their departing backs and giggled.

In the past few days since the beginning of the school year, I have studied two units of mathematics, which are negative numbers in the first unit, and cylinders and cones in the second unit.

The first unit was about negative numbers, which I had heard of since I was very young, but I didn't know what they meant and what they were useful for in life, and I didn't know whether 0 was an integer or a negative number. After studying this unit, all my questions have been solved. Numbers include positive, negative and 0, 0 is neither positive nor negative, it is the junction of positive and negative numbers, that is, numbers larger than 0 are positive, smaller than 0 numbers are negative, negative numbers are as important as positive numbers in terms of temperature, in summer, the outdoor temperature is often more than 30 degrees Celsius, the temperature at this time on the thermometer is above 0, is a few degrees above 0, and in the cold winter, if there is a snow, the outdoor temperature will drop below 0, which is a few degrees below 0.

When writing positive numbers, you can write "+" or not "+", if you write "+", you must have a "positive" in front of the number when reading. Negative numbers must be read with "-", and the word "negative" must be added before the number.

The second unit is the cone and the cylinder, I first learned the cylinder, the cylinder has a wide range of applications in life, we first learned the surface area of the cylinder, the surface area of the cylinder = the side area of the cylinder + the area of the two bottom surfaces, the two bottom areas are two circles, calculate the area of the circle I learned in the last semester, mainly the side area of the cylinder. The side edge of the cylinder is exactly a rectangle (sometimes a square) and the circumference of the bottom surface is the width of the cylinder when it is long, then the side area of the cylinder = the height of the bottom perimeter. With the formula for the surface area of a cylinder, we can calculate the surface area of many items, but some of them also need to be in line with the reality of life, such as a chef's hat, which only needs to calculate two sides, and a chimney only needs to calculate one side area.

The volume of the cylinder and the area of the circle are the same, the cylinder divides it into even equal parts, puts together an approximate cuboid, and finds the volume of the cylinder according to the method of finding the volume of the cuboid. After learning the volume of the cylinder, learn the volume of the cone, after testing, the volume of the cone is equal to one-third of the volume of the cylinder of the same height as the bottom, knowing this key clue The volume of the cone is much better, the volume of the cone = 1 3 The base area is high.

In these two units, I have a lot to pay attention to, negative numbers must be preceded by a negative sign, when calculating the surface area of the cylinder to conform to the reality of life, do not count the two bottom surfaces as one, do not forget to multiply the volume of the cone by 1 3 ......If you can remember these, only.