On national day, my mother gave me a gift, which is my dream badge machine. When I got home, I couldn't wait to unpack and do it. There are many accessories inside: Circular film, 3cm circular color paper, circular badge upper and lower covers, etc. I looked at so many accessories and didn't know how to start. I had to open the manual and study it for a long time to understand the production process.

    So I started making it according to the steps in the manual.

    First I found a piece of circular film and circular colored paper, and then I brought a set of badge covers. Suddenly I found a strange phenomenon. All the accessories inside are basically round, but they are different in size. I asked my mother, "how do you measure these circles of different sizes? Did you measure them with a ruler? Which accessory size does the 3cm on the box refer to?" my mother said, "I have a problem. First, I have to find a way to solve it myself." I replied angrily, "no problem, look at me." I quickly took the ruler. I found that none of the accessories was 3cm. What's the matter? On second thought, the finished product should be 3cm. Yes, it must be. I'm proud of my idea! My mother suddenly said, "can't you make the problem more clear?" after listening to my mother, I excitedly turned on the computer to search. I really don't know. I was shocked at the sight, but a small circle has endless mysteries. I found a lot of knowledge about circles, such as radius, diameter, PI, Zu Chongzhi and so on. Later, I successfully made a beautiful badge according to the steps, and then measured it correctly with a ruler. Sure enough, the diameter of the badge is exactly 3cm. Today's harvest is really big.