Mathematics, like a naughty elf, used to hate mathematics, but when I started to study hard, it was really interesting. It not only teaches me knowledge, but also brings me health. Maybe you will say, "How can math bring you health?" ? "That's because, every time I think about it, my body is very strong, so I'm healthy, hee hee, am I beside the point? Learn math, let our brains develop intelligence, classmates, do you like math? Do you know anything about math? Do you understand prime numbers and sums? If you don't understand, let me tell you something!

A prime number is a number with only 1 and its own two factors. It is also called prime number. For example, 2, 3, 5 and 7 are prime numbers.

A composite number is a number with two factors besides 1 and itself. For example, 4, 6, 8, 9, 12, 15 and 18 are all complex numbers.

extreme

Mathematics is everywhere, and there is a lot of mathematics in life. Let me tell you something about math in my life. One day after playing table tennis at school, I was very thirsty when I came out. My mother gave me 5 yuan and I bought 2 yuan. 7 yuan soda, the salesman gave me 2. 3 yuan, I went out with the money. I thought about it and bought her a 2 for 5 yuan. The salesperson should give me change for the 7-yuan soda. Three dollars, I thought about it, and I think there is a shortage of sales staff. As soon as I turned around, my mother asked me, "Where are you going?" I replied, "I bought her a 5-yuan 2." The salesperson should give me change for the 7-yuan soda. 3 yuan, she found less. " Mom smiled and said, "You are so stupid, 5-2. How much is 7? I said 3 o'clock. Three dollars. " Mom smiled and said, "Think again." "I said," it's 2 o'clock. 3 yuan, I miscalculated.

Be careful, but don't be like me!

Tisso

On Sunday, when I was at my grandma's house, I saw grandpa writing something seriously in the notebook, so I ran to see it. Grandpa told me, "this is grandpa's account book of water, electricity and natural gas, which is recorded every two months." I flipped through grandpa's ledger, turned to a page of natural gas and saw several figures, August, 3623, 3585, 38 cubic meters, 60. 8 yuan, only after asking Grandpa: 3623 is the reading on the natural gas meter in August, 3585 is the reading on the meter in June, and 3623-3585 = 38 cubic meters. Even if the natural gas used in June and July is included, the gas per cubic meter is 1. 6 yuan, 38 * 1. 6=60。 8 yuan, so I know how much natural gas is in June and July.

Grandpa is also in charge of water and electricity. Grandpa uses the most basic subtraction and multiplication in mathematics to keep accounts, and mathematics can be seen everywhere in life.

Article 4

Today, when we came to the shopping mall, we saw a dress. The original film is: 280 yuan has a 30% discount. Mom asked me, do you know what the price is now? I thought about the discount in the teacher's class, that is, using the original price * discount/10 = current price. I thought about it and told my mother to use 280 * 3/ 10 = 84 yuan. Mother nodded. When my mother and I saw something, we continued to go shopping. My mother said, "After 50% off, it will be 98 yuan." Mother asked, "Do you know its original price?" I'll tell my mom right away that it's 196 yuan. Mom asked me how you got it out so quickly. I said, "original price * 5/10 = 98,98 *10/5 = original price = 196 yuan. There is also the original price *1/2 = 98,98 * 2 =196 yuan. So the original price is 196 yuan. My mother nodded and said, "Good, I can use the math knowledge I have learned to solve problems in my life. "

Mathematics is indispensable in life, and mathematics cannot be separated from life. As long as we are good at discovering, mathematics is everywhere.

chapter five

On Saturday morning, my mother and I went to Dadai and saw activities going on inside. I went to see that goat milk powder was on sale, but it turned into buying three bags and getting one free. 36 yuan, 32 yuan and 28 yuan. Which is more favorable? I picked up a pen and counted it. 36 yuan 1 baoxian. It used to cost 3×36 yuan = 108 yuan to buy 3 packs, but now it costs 10 yuan to buy 4 packs. Now the package of 1 is 108 ÷ 4 = 27 yuan.

32 yuan 1 bag. It used to cost 3×32 yuan = 96 yuan to buy 3 bags, but now it costs 4 bags to buy 96 yuan. Now 1 Bao 96 ÷ 4 = 24 yuan.

Then calculate 28 yuan 1 bag. It used to take 3×28 yuan = 84 yuan to buy 3 bags, but now it takes 4 bags to buy 84 yuan. Now 1 Bao 84 ÷ 4 = 2 1 Yuan.

36 yuan offers 36-27 = 9 yuan, 32 yuan offers 32-24 = 8 yuan and 28 yuan offers 28-2 1 = 7 yuan. Through comparison, I found that the same buy three get one free, the higher the price, the more discounts, and the lower the price, the less discounts.

Ah, there is a lot of learning in life. As long as you observe carefully, you will find something.