Equations are very important for mathematics and are the basis for future study. The following equation, math diary, I prepared for you, hoping to bring you inspiration and thinking.
The first article: math diary about equations can meet many mathematical problems in his life. One day, I went shopping with my father and spent 130 yuan. My father wanted to test my ability, so he said to me, Son, suppose 10 yuan stands for A, 20 yuan stands for B, 50 yuan stands for C, and 100 yuan stands for D. How many equations can you list based on this information? I think, A+B+D= 130 yuan, A+B+2C= 130 yuan, A+6B= 130 yuan, 2A+3B+C= 130 yuan, 3a+5b =1. I said:? There are six kinds? . Dad said: I didn't know it was that simple. There are countless kinds. ! I thought for a moment and said: Ah! I only thought of addition and multiplication, not subtraction and division? . Dad said again:? You are wrong, too. Addition and multiplication are more than that. Why don't you go back and think for yourself? !
This time, my dad's question made me understand that when I encounter a problem, I should consider it comprehensively, scrutinize it carefully, and understand the meaning of the problem comprehensively and accurately, otherwise it is easy to ignore another answer and make a mistake of generalizing.
The second part: math diary about equations often meets some complicated problems in the process of solving practical problems, and needs to list equations to solve them.
In general, column equations can make complex problems simple. As long as we first find the equivalence relation from the topic, then find the unknown, and set X, we can easily list the equations. Therefore, the key to solve the application problem of column equation is to find the equality relationship. The more conditions there are in the application problem, the more complicated it is, but as long as the equivalence relationship is found, the problem can be solved.
Part III: math diary of the equation. Mathematics is everywhere in life. Now let's explore the mystery of mathematics together!
A few days ago, we learned to understand equations. This is not! As soon as I got home, my mother began to test me!
Mom opened the math book and asked, A box of ink is X yuan, and a pencil is 1.2 yuan. A box of ink and a pencil-4 yuan, how much is a box of ink?
I answered without thinking:? X+ 1.2=4 solution: x=4- 1.2 X=2.8?
? Good, good. ? Mom said with a smile.
? I haven't checked yet! ? So, I started to check again! :? Substitute x=2.8 into the left side of the original equation =x+ 1.2 =2.8+ 1.2 =4 right =4 left = right, then x=2.8 is the solution of the original equation. ?
? Yo! My daughter is very clever! ? Mom said with a smile. I laughed too.
? I'm testing you! ? Mom smiled mysteriously? A box of ink is X yuan, and three boxes of ink are 8.4 yuan, so how much is a box of ink? A box of ink is X yuan, and three boxes of ink are 8.4 yuan, so how much is a box of ink? What should we do! ? I asked my mother. Mom said:? You little fool, you just praised you, so you can't! Look, it says: X? 3=8.4! ?
? Oh, I remember! x？ 3=8.4 x=8.4？ 3 x=2.8. There is also checking calculation: test: put x=2.8 to the left of the original equation =x? 3 =2.8? 3 =8.4 right =8.4 left = right, then x=2.8 is the solution of the original equation. ?
? 100, depending on your enthusiasm, I'll give you another one: Xiaoming is x years old and his father is 40 years old. The difference between them is 28 years old. How old is Xiaoming this year? It's simple! 28+x=40 x=40-28 x= 13. Check to see if it is correct. ? Mom reminded me. Test: substitute x= 13 into the left side of the equation =28+x =28+ 13 =4 1! Left is not equal to right. Wrong calculation! Wrong calculation! x+28=40 x=40-28 x= 12 .？ You got it right this time! ? Mom gave me a thumbs-up sign! Let me ask you another question: At 8: 00 this morning, the water level of Hongze Lake dam reached 14.5438+04m, which exceeded the warning water level by 0.64m What is the warning water level? Solve by equation. ? I finally figured it out after scratching my head: solution: set the warning water level as xm warning water level+excess = today's water level x+0.64 =14.14x =14-0.64x =13.5 test: put x =/kloc-0. All right! I didn't expect to master new knowledge so firmly! I'll give you another question like this: A faucet in bright primary school is leaking. Xiao Ming carried the bucket for half an hour, and * * * carried 1.8 kg of water. Do you know a faucet that drips water every minute? I replied: solution: suppose a drip hose wastes xkg of water every minute? 30= dripping for half an hour1.8kg =1800g 30x =1800x =1800? 30 x=60 test: How about bringing x=60 into the original equation? Left =30x =30? 60 = 1800 right = 1800 left = right, so x=60 is the solution of the original equation! My daughter has grown up! ? Mom said with a smile.
You see, there is a lot of math around us!
Chapter 4: math diary of Equation These days, we have studied the equation. Through learning, I know that the equation is an equation at first, and it is also an unknown equation. Using the properties of equations, I learned to understand and test equations, and I also used equations to solve problems in my life.
I remember that during the winter vacation, I previewed the equation under the guidance of my mother. At that time, I thought it was very troublesome to solve problems with equations, and I had to regroup. I want to write a solution, at the same time, my thinking is still different from the original, and I feel very incomprehensible. Later, under the teacher's explanation, I finally understood that a good equation can be made by setting an unknown number and finding out the equivalent relationship between the unknown number and the known number.
My mother told me that we are learning simple equations now, and we will learn some complex equations such as binary equations and ternary equations in the future, so we can solve more problems then!
Now I think: it's good to learn equations!
Chapter 5: math diary of Equation Today we are going to learn equation. I think we have several key points to learn: for example, the format of solving equations should be several = should be aligned up and down. If there is a test, the following so should be aligned with the word test; Also, the calculation in the second step is very important during the inspection, so you can't write the answer in a hurry. When writing, carefully check whether the answer is equal to the right side of the equation.
There are several difficulties: it is a reciprocal relationship. If one party multiplies, the other party multiplies. After today's study, I learned a lot from it, and I can apply this knowledge to my future life. In the future, I will help my mother calculate how much one meter of lace costs; A question about how heavy lace is.
I will study math harder in the future, so that I can solve more life problems.
;