"Wonderful, wonderful, wonderful!" Math is really interesting. Not long ago, we learned a series of knowledge about fractions. How much is 3 divided by 4? I don't know, it's three quarters! That is, divide "1" into four parts on average, and take three of them, that is, fraction and division. Tell you, there are three kinds of scores, true score, false score and identical score. Fractions with numerator less than denominator are called true fractions, and fractions with numerator greater than or equal to false fractions are called with fractions.

Tell you a secret. Turning fractions into decimals can turn fractions into decimals and then into decimals. Divide it into decimal fractions, for example, 4/5,65438+8/00 equals 0.8. How's it going? Relax.

Can 65438+5823 in 07469 be divided into the simplest fractions? I can. The numerator and denominator have three digits and nine digits, and cannot be reduced by two or five. Then add up the digits of numerator denominator, 5+8+2+3= 18, 1+7+4+6+9=27. 18 and 27 are multiples of 3, divisible by 3, and equal to 194 1 in 5823. But now I don't know who to divide it by, but divide it by 3, and the denominator is exactly 5823, which means that the original denominator is three times that of the original numerator. 17469 divided by 5823 equals 3, 5823 divided by 5823 equals 1, 17469 5823 equals 1.

"Interesting, interesting, interesting, mathematics is really interesting!"

2. math diary pupils have 300 words in the fifth grade.

In the evening, my brother said he was hungry and wanted to drink milk powder. Seeing my mother washing clothes, I helped my brother make milk powder. But I didn't know how much water and milk powder I needed, so I ran to ask my mother. Mom told me that I need 180 ml of warm water. I asked my mother how many spoonfuls of milk powder she needed. My mother said, "How many spoonfuls of milk powder do you need for 30 ml of warm water, 1 80 ml of warm water? Calculate it! " When I added it, I counted 30: 30+30 = 60, 60+30=90, 90+30= 120, 120+30= 150,150+30. Finally, the sixth 30 adds up to 180. I quickly told my mother that it was six spoonfuls. Mom smiled and said, "That's right, but if you learn multiplication and division, it will be easier to calculate.". 180÷30=6, which can be calculated soon. " It can be that simple!

Mathematics is around us, I want to study it well!

3. math diary pupils have 300 words in the fifth grade.

Happy Saturday came, and my father and I went to work in the shop. As soon as I arrived at the store, my father got a call from a customer. I wanted to buy a batch of plates and put them on the insulation table. Dad answered the phone and said to me, "Dad tested you today!" " ! The customer wants to buy 4 sets of pots on the heat preservation table. 1 There are 6 sets of pots on the heat preservation table. A * * *, how much do you want? "I think in my mind, 6+6+6 = 24 (a). Dad asked again, "Do you have any other convenient and quick algorithms? "On second thought, I just learned the multiplication formula" 4624 "in the summer vacation, and I figured it out soon, and the answer is the same as that of addition. Dad gave me a thumbs-up when he heard the answer. Dad said, "The number of pots in our warehouse is 12. How many boxes do we need to send? " I quickly meditated in my mind that 24- 12- 12 = 0 is exactly two boxes. I quickly said to my father, "Two boxes will do. "Dad smiled happily and invited me to eat ice cream.

It turns out that mathematics is everywhere in our lives.

4. math diary pupils have 300 words in the fifth grade.

Life is inseparable from mathematics. Today I solved a shopping problem with math! My parents and I go shopping in the supermarket. I want to buy delicious BearBiscuit. Mom said, "There are two different kinds of packaging. Which one do you want to buy? " I carefully examined the two kinds of packaging, thought for a moment and said, "buy three boxes together."

Mother said, "Why?"

I excitedly said to my mother, "3 yuan's 50 cents a box is packed separately, 9 yuan's 90 cents a box is packed in three boxes, and 9 yuan's 90 cents is divided by 3." Each box is only 3 yuan and 30 cents, which is 20 cents cheaper than the individually packaged box. Three boxes have three different flavors. However, it is only a flavor of individual packaging. If you buy three different flavors, 3 yuan 5jiao x3= 10 yuan 5jiao, which is 6 jiao more expensive than three boxes, which is not cost-effective. Moreover, mom, you see, the net content on their packages is the same. "

Mom said happily, "Xixi is right. You can buy it if you say so."

It is very important to learn math well. Today, I applied the multiplication and division method I learned this semester to shopping, and I knew how to choose a more economical one!

5. math diary pupils have 300 words in the fifth grade.

This morning, I made an appointment with Xiaoming and Xiaogang to play a ball after school. After school in the afternoon, we happily came to the playground and began to racket balls. Xiaoming's filming is in full swing. Xiao Gang said: "We are racing against time to see who will make the most shots in 5 minutes!" "Then, he took out his watch from his schoolbag and asked," Who will come first? ""me! " Xiao Ming and I shouted in unison. Xiao Gang thought for a moment and said, "We use stones, scissors and cloth to decide. "The end result is the first Xiao Gang, I am the second, and Xiao Ming is the third.

It's time to start the game. Xiaogang picked up the ball and raced against time. Xiaoming and I are counting the time. Xiao Gang made 205 shots in 5 minutes, but I made more shots per minute than Xiao Gang 1 time, and Xiao Ming made fewer shots per minute than Xiao Gang1time.

Students, can you guess who is the first? Are there any achievements between Xiao Ming and me? Hurry up and use the math knowledge you have learned to help us calculate.

Ha ha! Have you worked it out? I shot 120, and Xiao Ming shot 195. You know who is the first.

Students, have you found that mathematical knowledge can be seen everywhere in our lives? Be sure to study hard and use it flexibly!

6. math diary pupils have 300 words in the fifth grade.

I met another math problem today, and it took me a lot of effort to solve it. The topic is: there are 30 birds in two trees, and 4 birds fly away from the second tree first. At this time, tree A flew to tree B with three birds, and the birds on the two trees were just equal. How many birds are there in each tree? As soon as I saw the topic, I knew it was a reduction problem, so I solved it by the method of reduction problem. But when I checked, I found something was wrong. I will do it again more seriously. I think there are as many as four missing, half of them are 13, and the restored B-tree is14; A tree is 16. The formula is: (30-4) ÷ 2 = 13 (only); 13-3+4 =14 (only); 30- 14 = 16 (only). The answers are: a tree 16 and b tree 14.

By solving this problem, I understand that no matter what I do, I should be careful, otherwise, even if I master the solution to the problem, the result will be wrong.