The sixth grade mathematics tabloid 1
Handbook of Mathematics for Grade Six II
Sixth grade mathematics tabloid 3
At noon today, I was doing my math summer homework. It's written. It's written. Unfortunately, I met a very difficult problem. I thought about it for a long time, but I didn't understand why. The question is this:
There is a cuboid, and the product of the front and top areas is 209 square centimeters. And long. Wide. All heights are prime numbers. Find its volume.
When I saw it, I thought: this question is really difficult! Only the product of two surface areas is known. You must also know that the required volume is long. Wide. Tall man. And there is no hint at all. How does this start?
Just as I was scratching my head. A colleague of my mother's came. He first taught me to solve it with the idea of equations. But I'm not very familiar with the method of equation.
So, he taught me another way: list the numbers first. And then rule them out one by one. Let's list a lot of figures according to the requirements of the topic first. Such as: 3. 5。 7。 Prime numbers such as 1 1. Then we began to rule out. Then we found that only 1 1 and 19 were left. At this time. I think: one of these two numbers is the front of the cuboid in the question. The common edge length above is the front of a cuboid. Divide the above by the sum of other side lengths (and the lengths are all prime numbers). So ... I began to distinguish which of these two numbers.
Finally got the result. It is 374 cubic centimeters. My formula is: 209 =119 = 2+171× 2×17 = 374 (cubic centimeter).
Later, I used what I learned this semester: decomposing prime factors to check this problem. The result is exactly the same.
After solving this problem. I am happier than anyone in my heart. I also understand a truth: mathematics is full of mysteries. Waiting for us to explore.