It has come to the end of the day, what are the feelings in your mind? Take immediate action to write a diary. How to write a diary will not be the same? The following is my collection of math diary 4th grade essay 7, welcome to read, I hope you can enjoy.

Math Diary 4th Grade Essay Part 1

This morning, we had an interesting lesson on OU. "Ding ding ding ......" The teacher walked into the classroom with a spring in her step. The classroom was quiet. The teacher said to us: "I first test you a question: two integers divided by the quotient is 12, the remainder is 26, the sum of the divisor, the divisor, the remainder of the quotient is equal to 454, the divisor is how much? I'm going to read it again, both ......". When I got the question, I thought to myself: how can I find the divisor without even knowing what the divisor is in this question? But then I recalled that my teacher always said that drawing line graphs is a magic tool for solving application problems. Why don't I give it a try? So, I began to draw a diagram: first, the divisor as a multiple, the divisor is how many times the divisor 26, and then draw the quotient and remainder. Oh, so it's a sum and multiple problem. The equation was: (454-12-26-26) ÷ (12+1) = 390 ÷ 13 = 30.

I thought to myself: we've learned how to calculate with x. I'll start by writing out the literal math. Divisor x Quotient + Remainder + Divisor + Quotient + Remainder = 454, then I set the divisor to X. The equation is: X x 12 + 26 + X + 12 + 26 = 454. I subtracted 12 and 26 first and then I was left with the divisor and the divisor, and then I subtracted 26 because there was a remainder in the divisor. Then I subtracted 26, so that the divisor ÷ the divisor is 12, and the divisor is 30. The equation is: X×12+26+X+26+12=454

Today is my mom's birthday. Mom goes to work in the morning and doesn't come back until the evening. When it was after 8:00 p.m., mom came back. When we were eating the cake, my mom said to me, "Mommy's going to test you, and if you get it right you can have a piece of cake, okay?" I said "No problem" and started to answer the questions.

Mom asked the first question: Mom is 36 years old, you are 10 years old, how many years older than you? Grandma's age is 6 times your age, how old is grandma? I quickly oral calculation of the results, I said: "Mom is 26 years older than me, grandma is 60 years old, it's too easy, I'll have my cake and eat it too". Mom laughed and said, "Proud, aren't you?" Another question: Xiao Ming is 8 years old, his dad is 40 years old, ask in a few years, dad is twice as old as Xiao Ming? Now I'm stupid, meditating, it seems that I can't have my cake and eat it, mom said, "How about that, it won't happen, right?" "Let me think again, think not I do not eat cake."

After a period of time I thought of a stupid way, I can find out their years of age ah, after a year of Dad and Xiaoming are a year older, and finally finally deduced that after 24 years of Dad's age is just 2 times the age of Xiaoming. I told my mom, she said there is an easier way, and then told me, as long as the father's age minus the age of Xiaoming is a number of years after the age of Xiaoming, that is, 32 years old, and then 32 - 8 = 24 years is the number of years passed. I suddenly realized that it can be so simple.

Mom said: I can think of my own way to get the results or good, as a reward for me to eat cake, I was happy and embarrassed, I can not be proud of the future, the children do not learn from me ah.

Do you know how many ways to solve the equation: 91 + 92 + 93 + 94 + 95 + 96 + 97? Maybe you think there is only one or two, then let me tell you that there are three ways to solve this problem.

The second: because of these, are very close to 100, we see the seven numbers as 100 plus, so that more than 9 + 8 + 7 + 6 + 5 + 4 + 3, and finally 700 subtracted from the sum of these numbers can be.

The third: these 7 consecutive natural numbers, 94 in the center, the first number 91 is 6 less than the last number 97, and then divide the 6 to 91, so that 91 and 97 into 2 94, similarly, 92 and 96, 93 and 95 can be turned into 94, so that the 7 numbers become 7 94, the original question becomes:

Let's talk about counting the workbooks. How long will it take us to count 100 workbooks?1 book, 2 books, 3 books ..... ...100 books, it takes about 110 seconds. And how many seconds does it take to count 1,000 workbooks, 10,000 workbooks, 100,000 workbooks ..... .how many seconds does it take for 100,000,000 workbooks? Just do the math to find out how big 100 million is.

Doing the math, it takes about 11,000,000,000 seconds to count 100,000,000,000 workbooks, so imagine how many minutes it takes to count 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 workbooks? How many hours, how many days? How many years / roughly to 1833333 minutes, 30556 hours, 1273 days, 3 years! It takes 3 years to count 100 million workbooks!

Math Diary 4th Grade Essay Part 2

On Saturday afternoon, I finished my homework and had nothing to do, so my mom gave me a question: do you know what are the characteristics of multiples of 2? I heard and answered at once: they are all doubles. Then what are their characteristics? Mom asked again. They all have 0, 2, 4, 6, and 8 in their digits.Mom said: you are great. Then do you know `multiples of 4 know the characteristics? This can be difficult for me.

So I looked for some multiples of 4, and found that their digits are also 0, 2, 4, 6, 8, so I told my mom about this pattern. But mom casually said a number and overturned my discovery. Mom told me to keep observing, but I still couldn't find it by looking left and right. Mom then gave me a reminder: look at the last two digits of these numbers. According to my mom gave me a hint, right these numbers to observe a bit, suddenly suddenly realized.

Doing homework: It turns out that multiples of 4 are characterized by the fact that if the last two digits of a number are multiples of 4, the number is a multiple of 4. Then, I found some numbers to try, for example: 437, 37 divided by 4 = 91, according to the law 437 is not a multiple of 4, I then divided by 437 = 1091, in line with this feature. I found another number 1024, 24 divided by 4 = 6, looking for the law 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 mom about this discovery, and she nodded with satisfaction.

This is my discovery, students may want to try.

Math Diary 4th Grade Essay Part 3

Saturday afternoon, I did my homework and idly, my mother gave me a question, "Do you know what are the characteristics of multiples of 2?" When I heard it, I answered at once: they are all doubles. "What are the characteristics of this them?" Mom asked again. "They all have 0, 2, 4, 6 and 8 in their digits. "Mom said, "You are amazing. This you know that multiples of 4 know the characteristics?" This is difficult for me.

So I looked for some multiples of 4, and found that all of them also had 0, 2, 4, 6, 8 in their digits, so I told my mom about the pattern. But mom casually said a number and overturned my discovery. Mom told me to keep observing, but I still couldn't find it by looking left and right. Mom then gave me a reminder: look at the last two digits of these numbers. I according to my mother to give me tips, right these numbers observed some, suddenly suddenly realized.

It turns out that multiples of 4 are characterized by the fact that if the last two digits of a number are multiples of 4, the number is a multiple of 4. Then, I found some numbers to try, for example: 437, 37 divided by 4 = 9......1, according to the law 437 is not a multiple of 4, I then divided by 437 = 109......1, in line with this feature. I looked for another number 1024, 24 divided by 4 = 6, looking for the law 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 mom about this discovery, and she nodded with satisfaction.

This is my discovery, students may want to try.

Math Diary 4th Grade Essay Part 4

Today, I followed my mom to the grocery store. Mom said, "Today I'm going to test you to see if you can buy a kind of vegetables you like to eat by yourself." Mom gave me 20 yuan to see how I would do. "Promise to finish the task." I said confidently. So, I walked and came to the vegetable section. At that moment, I saw an aunt selling white, fresh mushrooms. I thought: the green vegetables left at home can be eaten in soup with the mushrooms. So I asked the seller, "Auntie, how much do mushrooms cost per catty?" The aunty said to me with a smile, "Little friend, this mushroom costs 7 yuan a catty, how many catty do you want to buy?" "Auntie, I just want to buy half a catty." I thought: 7 divided by 2 equals 3.5 yuan, 20 minus 3.5 equals 16.5 yuan. Thinking about this, I gave the aunt a 20 yuan bill and told her to find me 16.5 yuan. I also came to the meat area, saw an uncle selling meat, then asked: "Uncle, strip meat how much yuan a catty?" "10 yuan a catty." "I'll take a pound of that." I thought: 16.5 minus 10 equals 6.5 yuan. I handed the uncle 10 yuan of the 16.5 yuan.

When I came out of the grocery store, my mom smiled and said, "You've learned how to shop for food!" when she saw that I had both meat and veggies in my hand and 6.5 yuan.

Through this test, I feel that there are many mathematical mysteries hiding in our lives, and it is really important to learn the skills of math. Moreover, we should not be proud of ourselves, and we should work hard to learn and master more math skills, so that we can apply them to solve the problems around us.

Math Diary 4th Grade Essay Part 5 4th Grade Math Diary Essay 1

Monday, October 6 Sunny

This morning I accompanied my mother to go shopping in the supermarket, where there were a lot of things to eat, drink, use, and many toys. We first came to the food area and bought a box of Holliday Pie which I like to eat for 15.7 yuan, and my mom gave me 100 yuan to go to the checkout. 100-15.7=84.3 yuan.

We also came to the vegetable area, mom bought green peppers 2.2 yuan. Chestnut 12.4 yuan, bean sprouts 4.8 yuan, potatoes 4.4 yuan, in the vegetable area we *** spent (2.2 + 12.4 + 4.8 + 4.4 = 23.8 yuan), 84.3 yuan minus 23.8 yuan, and now there is still 60.5 yuan left. I want to eat milky buns, we went to the deli area, bought a bag of milky buns spent 5.9 yuan, 60.5 yuan minus 5.9 yuan, there are still 54.6 yuan left, my mother asked me how much money I spent on a line in a ****? I calculate (15.7 + 23.8 + 5.9 = 45.4 yuan) How much is left? Mom gave 100 yuan, we spent 45.4 yuan (100-45.4 = 54.6) the last remaining 54,6 yuan.

What a fun day at the supermarket!

Fourth grade math diary essay 2

On the weekend, my mother sat in front of the computer online Taobao. I asked my mom what to buy? Mom said, "It's almost New Year's Eve, I want to buy a pair of shoes for each of you and your sister." I asked, "Mom, why not go to the store to buy it?" Mom said; "I fancy shoes marked price of 200 yuan per pair, the store 20% discount sale, that is 160 yuan per pair, you calculate how much for two pairs?"

I hurried to calculate: 160 * 2 = 320 (yuan)

Mom said: "Calculated well, then you calculate online 60% off, 120 yuan per pair, how much for two pairs?"

I went on to say: 120 * 2 = 240 (yuan)

Mom asked again, "Then you calculate how much cheaper it is to buy online than in the store?"

I said aloud: 320-240=80(yuan)

Mom said, "You're pretty fast at calculating, now you know why we don't go to the store?"

I said, "I know, so when do we get our new shoes?"

Mom said, "The courier will be home by noon tomorrow, so just wait to receive them."

Math Diary 4th Grade Essay Part 6

The other day, the teacher put this question on the board: two pens and a ballpoint pen **** $16, two ballpoint pens and a pen **** $11. So how much is a fountain pen?

After writing, the teacher said, "You have 10 minutes." I hurriedly lowered my head and began to do the topic. I thought and thought and thought, but I could not think of anything, and by then 4 minutes had passed. I was as anxious as an ant on a hot pan, afraid that all the other students would do it, but only I couldn't do it. If I was criticized by the teacher on the spot, wouldn't it be a shame? How I wish there was a beautiful fairy to tell me what to do! In the blink of an eye more than two minutes have passed, I secretly look around to the students, only to see that some of them hold their chins seriously thinking, some dead look at the question, and some with me, looking around.

The teacher walked around and came back to the podium and said to us, "You can try to change the words into equations!" Hearing the teacher say so I quickly wrote two equations on the paper. 2 steel + 1 round = 16 yuan; 1 steel + 2 round = 11 yuan. My eyes lit up and I was secretly happy. The difference between 16 and 11 is the price of a fountain pen over a ballpoint pen! I thought I could do the math right away, so what's next? What's the use of this 5? I'm so happy for nothing, I can't do it if I stop here, I'm not happy for nothing! I hung my head down on the table. The teacher seemed to read my mind, came to my side and reminded me: you can use the hypothetical method and imagine the situation when you buy a pen. After my teacher said this, I felt enlightened: If I don't buy this ballpoint pen, the boss will have to pay me back 5 dollars. If I don't buy the ballpoint pen, the owner will give me back 5 yuan. Then 3 ballpoint pens will cost 6 yuan, and each ballpoint pen will cost 2 yuan.

Such a difficult topic was cracked. It turns out that as long as you use your brain more, you can make it very easy.

The first Harry Potter book, "With the Sorcerer's Stone", costs 19.5 yuan and has 191 pages. 19.5 ÷ 191 ≈ 0.1 (yuan), a page costs about 0.1 yuan, and the book was issued in 1391500 copies. If all sold can income 1391500 × 19.5 = 27134250 yuan!

The second book, "The Chamber of Secrets", was priced at $22 and had 203 pages. 22 ÷ 203 ≈ 0.11 ($), the price of a page in the second book was 1 cent more than in the first book. There were 1,271,500 copies of this book distributed. All of them can be sold to earn 1271500 × 22 = 2793000 yuan!

The third book, "The Prisoner of Azkaban," costs $26.50 and has 260 pages. 26.5 ÷ 260 ≈ 0.1 ($). The price of a page in the third book is the same as in the first book and 1 cent less than in the second book. There were 1271500 copies of this book distributed. All sold can income 1271500 × 26.5 = 33694750 yuan!

It turns out that the second book has the highest price for one page.