We also learned the properties of decimals. The essence of decimal is to add "0" or remove "0" at the end of decimal, and the size of decimal remains unchanged. From this conclusion, we can do two kinds of questions, one is simplification and the other is rewriting. Simplification means removing the zero at the end, and rewriting means removing the zero at the end or adding zero to see how many decimal places the topic needs.
We also learned how to read and write decimals and how to multiply and divide decimals. Multiplication and division of decimals means that decimals are simplified to 110,1,100,1/000. ..................................................................
We also know that mg is the unit of mass, 1 g = 1000 mg.
This is my harvest in a week, hehe, it's quite interesting.
Every notebook week in the fourth grade mathematics, we learned a new lesson-statistics.
We have this statistical unit in every book. The most important thing in statistics is to average, because only in this way can it be better. The average value is as follows: total number ÷ total number of copies available.
We also learned a content: parallel bars statistics. We have studied simplex statistics before. There are usually some statistics on parallel bars, which are for you to fill in. The method of filling in is to use a symbol to represent a number, which is not easy to confuse statistics. I am because of this wrong question. My easy mistake is to add the wrong number, and then I am wrong. There are other topics, such as skipping: one group of four people jumped 360 times, while the other group of four people jumped 100 times on average. How many times do these two groups dance on average? I was all wet. I didn't see a * * * and the average clearly, so I counted them as the average. I will pay attention to the problem before I do it.
This is my harvest in a week.
In the third week of fourth grade mathematics, we learned new knowledge and observed objects.
Generally speaking, the same object may have different shapes from different angles. There are many objects whose shapes are completely different from different angles, such as a cylinder, which is round from above, and may be square or rectangular from the side and front.
When there are several small cubes in a graph composed of a group of small cubes, the best way is to look from the top first and then from the side. If there is a bulge, there must be a small cube below.
When drawing a graphic section consisting of a set of cubes, the front row is drawn in the back and the back row is drawn in the front.
This is my harvest in a week.
Continue to learn decimals this week, mainly unit conversion and divisor.
We studied the unit rate table:
Unit of length: kilometers (1000) meters (10) decimeters (10) centimeters (10) millimeters.
M (1000) mm
Cm (100) m
Area unit: square kilometer (100) hectare (10000) square meter (100) square centimeter.
Square meter (10000) square centimeter
Weight unit: ton (1000) kg (1000) g.
RMB: Yuan (10) jiao (10) fen.
Rmb (100) point
Knowing this rate table, we can do many types of problems, such as turning a single number into a single number (one unit is called a single number) and turning a single number into a composite number (two units are called a composite number). How should I change it specifically? Large units become smaller units, magnification, decimal point moves to the right, small units become larger units, divided by magnification, decimal point moves to the left.
In addition, we also learned how to find approximate values from decimals and rewrite them. Decimals, like integers, are rounding methods. When approximating, keep the integer as the nearest unit, one decimal as the nearest tenth and two decimals as the nearest hundredth.
I learned this knowledge this week.
This week, we learned the addition and subtraction of decimals.
Matters needing attention in addition and subtraction of decimals are as follows: the decimal points of decimals should be aligned, and then the decimals in ten directions should advance 1 from the last number. Don't forget to add decimals and decrease the numbers. Some operation rules in integers are also used in decimals, such as additive commutative law and additive combination law, such as 0. 1+0.9+0.3=? The additive combination law can be combined into (0. 1+0.9)+0.3, which can be simplified. For example: 0. 1+0.9 additive commutative law is 0.9+0. 1. Of course, the addition algorithm can also be used.
I also know how to find the addend. When finding the addend, I can find another addend by adding and subtracting this addend. I also know how to find the minuend by subtracting the minuend. I also know how to find the minuend by adding and subtracting the minuend. Especially when the number of minuend digits is not enough, it is necessary to fill the number of minuend digits with zeros to make the number of minuend digits equal to the number of minuend digits.
This is my harvest in a week.
On Saturday afternoon, I finished my homework and had nothing to do. My mother gave me a question: "Do you know the characteristics of multiples of 2?" As soon as I heard it, I immediately replied: they are all even numbers. "What are their characteristics?" Mom asked again. "Their units are all 0, 2, 4, 6, 8." Mom said, "You are really something. Then do you know the multiple of 4 and know the characteristics? " Now you have me stumped.
So, I found some multiples of 4 and found that their units are also 0, 2, 4, 6, 8, so I told my mother this rule. But my mother casually said a number, which overturned my discovery. Mom told me to keep watching, but I couldn't find it left or right. Mom reminded me: Look at the last two digits of these figures. I observed these figures according to the tips my mother gave me, and suddenly it dawned on me.
The original multiple of 4 is characterized by the fact that the last two digits of a number are multiples of 4, and this number is multiples of 4. Then, I found some numbers to try, such as: 437,37 divided by 4 = 9... 1. According to the law, 437 is not a multiple of 4. Then I divide 437 by 4 = 109... 1, which is consistent with this feature. I found another number, 1024, 24 divided by 4=6. I found that 1024 is a multiple of 4. I verified it again by division: 1024 divided by 4=256, so 1024 is a multiple of 4. I happily told my mother about this discovery, and my mother nodded with satisfaction.
I found this. Students might as well give it a try.
Fourth-grade math weekly diary 7 Mom asked me to calculate an account today:
My first tuition fee is 5000 yuan, plus living expenses is 5000 yuan, which is 5000*2 5000 = 15000 a year. It takes 15000*6=90000 yuan from grade one to grade six, and it takes six years from junior high school to senior high school, at least 20000 * 6 = 65400 yuan. 90000 12000 80000=290000 yuan, I will study hard in the future, not afraid of failure, and I will do well in junior high school, asking the school not to charge me tuition.
Today, I counted the number of pages and words in the book Free Travel in Thailand. I think it is difficult to count the number of words in this book, because every page of this book has at least one picture, and some are full pages of pictures. I browsed the whole book, and it is estimated that there are 500 words on an average page. I randomly counted 10 pages, then estimated the thickness of 50 pages according to the thickness of 10 pages, and then estimated the thickness of the whole book to be more than 3 pages, which should be more than 150 pages or even more than 20 pages. Then, the total number of pages in this book should be 50 * * * 3+20 = 6544. I estimated the number of pages and words. I turned to the last page, and sure enough, this book is 160, and my calculation is more accurate.
Math Week 9, Grade 4 Math, Math I love you, just like a mouse loves rice. Do you know why I like math? Because of the charm of mathematics, it attracted me deeply.
I learned a new knowledge today, which is a simple addition and subtraction algorithm. After learning the simple addition and subtraction algorithm, my calculation speed is much faster and it is easier to learn to calculate. Give an example! For example: 367+498=? I just have to think like this: add up 498 to make 500, and then use 367+500. I found that I added 2 more, so I subtracted 2 from the total to get 865. And 796+295? I think so: 796 can be added to 800, 295 can be added to 300, one plus 4 and one plus 5, then the formula becomes 800+300-4-5 = 109 1. Look, how convenient it is!
After learning the simple algorithm of addition, learning the simple algorithm of subtraction will be much easier. Such as: 483-299, hehe, you can find the way by gently moving your head. I'll take 299 and subtract it from 300, because it's 1, so just add 1 to the result, which is 483-300+ 1 = 184, and the calculation is much simpler. However, I can warn you: it's best not to think about the minuend when doing subtraction, or you'll be in trouble!
Now, I like math more and more, because it makes me learn to calculate the results quickly, and math really makes me remember deeply.
Weekly Record of Grade Four Mathematics 10 Today is Saturday, May 6th. It's sunny and sunny. What a nice day! I quickly brushed my teeth and washed my face, and then I went to perform the task my mother gave me. Today, she asked me to take 20 yuan's money to a fruit shop to buy three kilograms or four kilograms of fruit. I hurried to the fruit shop and asked the assistant aunt first, "Aunt, how much is this apple a catty?" Aunt answered that apples cost 4 yuan a catty. I asked my assistant aunt to weigh me 4 Jin and hand my aunt 20 yuan. Aunt gave me the weighed apples and got my 3 yuan money back. I don't think it's right to take money, so I immediately calculated it carefully: one catty of 4 yuan, four catties is four 4=4×4= 16 yuan, and then use 20- 16 yuan. I confidently told my aunt that she had miscalculated, and then quickly told me the calculation process. My aunt insisted on getting my one yuan back, and her face was a little embarrassed. But when I left, I praised my math study. I was embarrassed to blush after listening to it, but I was still very excited. I was determined to continue my efforts and strive for better math in the future!