I knew that I had made a mistake.

It is 1

The last product is 99.

Let's start with 1.

A few days ago, I sent a test paper to the students, and there was a fill-in-the-blank question: the smallest number was (). When talking about papers, I told students that the smallest number is 0, because 0 is a number, so it is a number, and 0 < 1 is the smallest number. As soon as the voice fell, Tian Da stood up and said, "Teacher, the smallest number I saw in the primary school newspaper is 1, not 0." After listening to his words, my heart couldn't help pounding. Am I really wrong? Tian Da is a little genius in my mind. He is very clever. He said that the primary school report must be correct. I paused. "Oh, can you show the newspaper to the teacher?" He rummaged through his schoolbag and took out his newspaper. I saw an article entitled "What's the smallest number?" , indicating that the smallest number is 1, not 0. So I quickly asked my classmates to take out their newspapers and read this article carefully: First, when talking about the number of digits, it is stipulated that the highest digit of a number cannot be 0. For example, no number is expressed as 0325, but only 325, which is a three-digit number with the highest bit of 3, instead of saying that 0325 is a four-digit number with the highest bit of 0. It can be seen that the highest number in a digit cannot be 0, so 0 is not a digit at all. In addition, if 0 is the smallest number, then the smallest two digits are 00, and the smallest three digits are 000 … and this conclusion is obviously wrong. To sum up, 0 is not a number, let alone the smallest number. "What kind of number is 0?" Most students have raised such questions, so I immediately seized this opportunity to assign this homework to my classmates and let them go home to check the information. The next day, many students found the answer to the question: 0 means nothing, which is the smallest natural number, and 0 also means the starting point and the beginning. "What is the smallest number?" This question makes me reflect. It seems that I should learn from my students. In teaching, we can't rely on our own experience in everything, and we must be clear and accurate about uncertain problems. Read more newspapers and magazines in your spare time to enrich yourself.