Hey, have you ever noticed the long string of numbers on your ID card? Sometimes, you find that the last digit of these numbers is an "X", don't you think it's weird? What does this "X" mean? Is it pronounced "cross" or "Ex"?
Let's first understand the meaning of the 18-digit ID number
Every number on our ID card has its specific meaning. Our ID number is made up of four parts, like a little story, each part tells us a different message.
Digits 1-6, address code—:
Digits 7-14, Date of Birth:
The 15th-17th digits, the sequence code: In particular, there is a secret in the sequence code, that is, the odd number represents the boys, and the even numbers represent the girls.
The 18th bit is the most mysterious checksum:
There are 11 possibilities for this checksum, and the number from 0 to 9 is normal, but if the calculated result is 10, then the last digit will be replaced by an "X".
What does the tail number "X" mean?
You might ask, why use an "X" instead of a 10? Actually, the "X" is the 10 in Roman numerals. Roman numerals are a type of numeral used by our ancient Europeans, and although they are used less now, we can still see them in some special places, such as clocks.
Therefore, the "X" on the ID card is actually the Roman numeral 10, which should be read as "ten" and "ten" in English.
However, when we usually speak, many people are still accustomed to pronouncing the "X" on the ID card as "cross" or "Ex", which sounds smoother and easier to understand. Actually, you can read it no matter how you want to read it, but the important thing is that we know the secret behind this "X".
Now, do you have a deeper understanding of the "X" on your ID card? In fact, there are many little secrets like this in life waiting for us to discover. As long as we observe carefully and think carefully, we can discover the wonder and interest of this world.
So, the next time you take out your ID card again, you might as well take a closer look at that mysterious "X" and imagine the story behind it. You may think that this little "X" is actually a bridge between the ancient and the modern, so that we can feel a little bit of history and cultural charm in our busy lives.
In general, every number on the ID card has its meaning, and the mysterious "X" is one of the most interesting passwords. The next time you see it, try to unlock its secrets, and maybe you'll discover a whole new world!
Okay, let's talk about this today, quickly forward it to the friends around you, and increase knowledge together!