Nanjing Cuipingshan Primary School Wu (3) Fang Xiaoxiao

The world is full of wonders, and there are many interesting things in our mathematics kingdom.

Once, I went to my uncle's factory to play.

I am having a swell time. Then I found a pile of steel pipes and became interested. I counted, this pair of steel pipes has 18 layers. I have been counting. When I counted 95 steel pipes, I was confused by the barking of a dog. I don't know where to count, so I have to count from the beginning. The branch counted, "Oh, I forgot again." I have to count. Counting, "I forgot again." I have to start over. ...

Although I lost count of the number of steel pipes countless times, I didn't give up. Finally, I counted 1044 steel pipes. At that time, my uncle came and I asked him; "Uncle, why is this pile of anal canals so difficult to count?" Hearing this, my uncle smiled and said, "Didn't you learn the area of a trapezoid? Why not calculate the area of the trapezoid? " I calculated the area of the trapezoid: top 20 (the upper bottom of the trapezoid), bottom 38 (the lower bottom of the trapezoid), with 18 floors (the height of the trapezoid), and the area is (20+38)× 18÷2= 1044 (root).

In daily life, there are often many problems that can be solved with mathematical knowledge. As long as you wake up your life experience and scrutinize it carefully, you will know how to do the topic. (Instructor: Li Jingjing)

Small numbers are everywhere.

Nanjing Cuipingshan Primary School Wu (3)

There are many places where mathematics is used in life. This time I want to talk about the application of decimals in life.

Seeing decimals reminds me of many places where decimals are used in my life. For example, in a supermarket, the place where fruits are sold will be marked with 6.58/500 g; In shopping malls, the label of clothes will say 50.80/ piece, and some vegetables in the market sell for 3.68/ kg. At the stationery store, a pencil case 18.98 yuan and a revised sticker 1.5 yuan, 0.5 yuan and mechanical pencil. ...

Speaking of decimals, you will think of how to apply decimals. At the supermarket checkout counter, if you pay the cashier the whole money, she will give you change. For example, if you pay the cashier 50 yuan 48.56 yuan, she will give you 1.44 yuan. For example, you bought two correction stickers in a stationery store, and used 1.5+ 1.5=3 yuan, and you have to pay 3 yuan.

Speaking of the benefits of decimals, there are many. For example, if you want to build a building, you must have accurate data, and there must be decimals in these data. Otherwise, it will be difficult for Gai Lou. If it is less, it may make a big mistake; On the thermometer, there are many temperatures with decimals, such as 26.8. C.34.5. C ... This will enable climatologists to conduct scientific research better. There are many advantages of decimals, which should be left to us to discover.

Decimals are everywhere in our lives, which brings great convenience to our lives. We should make good use of it! (Instructor: Li Jingjing)

Mathematics in the shopping center

Nanjing Cuipingshan Primary School 5 (1) Chen Yilin

I have knowledge of mathematics everywhere in my life. When I entered the mall, I found that shopping is a science, so I have to make a good calculation.

The national day is coming, and the mall is promoting sales and discounts. I just want to buy something: a pair of pants, a backpack and a happy toy. My mother gave me 100 yuan to count the flowers myself.

I'll go to a shopping mall to look at my pants first. The brand's activity is 60% discount. The original price of 88 yuan's trousers in 52 yuan is 80 cents, and the original price of 68 yuan's backpack in 40 yuan is 80 cents. Toys 10 yuan are not discounted, so if I buy all three things in a shopping mall, I have to pay 52.8+40.8+10 =103.6 yuan. We don't have enough money, and we need 3.6 yuan.

I went to the nearby shopping mall B, where there was an activity for 68 yuan to send 68 yuan. I have a look. small backpack of the same brand can get a coupon from 68 yuan after buying it, which can be used to buy pants. The original price of trousers is 88 yuan, and there is no discount. I only need to pay the voucher of 88-68=20 yuan, and the toy is also at the same price 10 yuan, so I have to pay 68+(88-68)+ 10 = 98 yuan to buy these three things. Not only did I not overspend, but I also saved 2 yuan.

I really don't know, but I'm shocked. It turns out that shopping is also very learned! It seems that learning math well is really useful. I will study mathematics harder in the future and use it flexibly in my life.

(Instructor: Zhang Zhengxiang)

Businessmen's "painstaking efforts"

Nanjing Cuipingshan Primary School Wu (2)

The world is full of miracles, and there are many interesting things in our learning kingdom. Many things happen in our daily life.

During the "Eleventh" period, it is rare for our family to spend holidays together. I took advantage of this good opportunity to go to the mall with my parents. On the second floor, we took a fancy to a suit, and its price tag was 520 yuan. The salesman said, "It's just in time for the Eleventh. Over 200, you can choose to get a 20% discount or return to 160. Both are similar. "

Is it really similar? I have such a problem in my mind. If you choose a 20% discount, it will cost 520×0.8=4 16 (yuan) and it will cost more than 200 yuan to return 160. We only need to pay 520 yuan first, and then we will get a rebate of 160×2=320 (yuan), so we actually spent 520-320 = 200 (yuan). Compared with 200, 4 16 is certainly the second one.

But what about after getting the roll back? If you buy something from 320 yuan again, you can return it to 160 yuan, and the discount of 160 yuan is only 200- 160 = 200 yuan starts from 40 yuan. If you want to buy something from 40 yuan, you can return it to 160 yuan. Don't you have a crush? But if so, you will fall into a bottomless pit. 200 yuan spent 160 yuan, 200 yuan spent 160 yuan ... so you will never spend the rest of the money. Merchants really try their best to make money.

In daily life and study, there are often many math problems that can't be seen only superficially, but should be understood more deeply. Because in many exercises or exams, the correct answer is easily overlooked, which requires us to carefully examine the questions, awaken the experience of life, carefully scrutinize them, and fully and correctly understand the meaning of the questions. Otherwise, it is easy to ignore other answers and make a mistake of generalizing.

(Instructor: Li Jingjing)

Only for reference, the key is to write it yourself!