Kneel down and ask for a math diary of about 400 words!! Don t be too na ve, like grocery shopping,

On Saturday, his mother gave Xiao Ming a "heavy responsibility" - to go to the market to buy fish.

The market is crowded and bustling. Xiao Ming squeezed into the fish area, and just saw Uncle Ma selling fish, Uncle Ma's fish are all live fish, very fresh, so a lot of them were bought, but there are still some crucian carp left, and although there are few, but all of them are alive and jumping, trying to break free from the constraints of the basin.

Xiao Ming said: "Uncle Ma, I am a frequent customer of yours, sell all these fish to me, cheaper." ”

When Uncle Ma heard this, he laughed and said, "You will bargain at a young age, okay, give you a chance!" Then he took the scale, and weighed it with the basket, and said,

This basket of fish originally weighed 28 kilograms in a basket, a restaurant bought half of it at a time, and then another customer came and bought the remaining half, and now the basket weighs 14 kilograms, can you count how many kilograms of fish are left, I will sell it to you at the lowest price! ”

Xiao Ming is a stubborn person who does not admit defeat easily, he used his brain to think: "38 kg and 14 kg both contain the weight of the fish basket, and 24 kg can be sold with 38-14. Then I think about it backwards and think that the fish left now is one serving, and there are two servings before the customer comes, so we can know that there are two more servings before the customer comes, and the fish bought by the restaurant is two servings, so the fish in the basket is originally four servings, and a total of three servings were sold.

Thinking of this, Xiao Ming said happily: "I have calculated it, now there are 24 3 8 (kg) left in the basket, and this fish basket weighs 2 kg!" ”

Uncle Ma gave a thumbs up and praised: "Xiao Ming is really amazing, okay, I will fulfill the promise I made just now!" ”

Mystical leap years.

Today, the teacher is reviewing the time unit and mentions the common year leap year, which is a year that only happens once every four years. In that year, there would have been 29 days in February, and 366 days in the year, which I understand, because the time for the earth to orbit around is about 1 4 days out of 365 days, and after four years there will be an extra day, which will be added to February, which has the fewest days.

However, what I don't understand the most is why a whole hundred year is a leap year if it is a multiple of 400, like 1900 and 1800, which can be divisible by 4, and should also be counted as a leap year, why does it have to be a multiple of 400?

In order to find the answer, I looked through the books, but I didn't find the answer, I only got a data, the time of the earth's revolution is 365 days, 5 hours, 48 minutes and 46 seconds, and I thought: Hey, maybe I can calculate it through this.

Let's do it, I first convert 5 hours and 46 seconds into 20926 seconds, a day has 86400 seconds, with 20926 86400 days), this is the number of days that people count less per year, so multiply this number by 4 equals days, people for simplicity, they see it as a day, and in this way they count more days) = 46 minutes and seconds, and then use 46 minutes and seconds (100 4) = 19 hours and 12 minutes, which is the more time calculated in each hundred years, People think of these times as if one day is not attached to the other 99 (100-1) years, and in this way, there are more hours, and in this way, every four hundred years there are more days, and almost one day, so that four hundred years and one leap, i.e., 100-3 = 97 (years), so there are only 97 leap years every four hundred years.

Oh! It turns out that this is the case, the hard work pays off, and it is finally calculated, although it is quite troublesome, but it also unravels a knot in my heart. That feels awesome. In fact, mathematics is very close to our lives, almost everywhere, as long as we are careful, there will be many gains!

I don't have time, I don't mind if you write about the mathematics in your life, what you feel and gain, it's very easy to write, write it yourself.

What's? Imagine a 100-foot child. You can't write your own diary, do you? What a hatred for children.

What's it?,I can't write it myself.,Can't you just copy and change it?。

Today, I came across this incredible statistic in a book: "How can a piece of paper with a thickness of centimeters be higher than Mount Everest after being folded in half 30 times?" ”

No matter how you listen to this data, I think it's a little too "ridiculous". After all, it is a thin piece of paper, can it really surpass Mount Everest by folding? But a lot of unexpected things can happen, so it is only through calculations that the mystery of all this can be revealed.

Immediately, I multiplied the centimeter by 2 consecutively, for a total of 30 times, to get the centimeter. Then, I converted the height of Mount Everest into 884813 centimeters, and by comparison, it was clear that the thickness of the paper after 30 folds was indeed better than the height of Mount Everest, and it was more than 10 times that of the latter.

In fact, amazing data like this is everywhere in ordinary life, as long as you have a pair of eyes that are good at discovery.

Today at noon, I was doing my math summer homework. Writing and writing, unfortunately encountered a difficult question, I thought about it for a long time and didn't come up with a reason, this question is like this:

There is a cuboid with the product of the two areas on the front and above being 209 square centimeters, and the length, width, and height are all prime numbers. Find its volume.

When I saw it, I thought, "That's a really hard question!" Only the product of the two surface areas is known, and the volume must also know the length, width, and height, and it doesn't hint at all. How do you get started?

Just as I was scratching my ears and cheeks in a hurry, a colleague of my mom came. He first taught me to use equations to solve, but I was not very familiar with this method. So, he taught me another way:

List the numbers first, then exclude them one by one. We first listed a number of numbers according to the requirements of the question, such as prime numbers such as , and then we started to exclude, and then we found that there were only two numbers left, 11 and 19.

The sum of the edges (and the lengths are prime). So, I began to tell which of the two numbers was which.