The original number of the question "Doing" on page 13 of the first volume of the fourth grade mathematics of People's Education Edition is 84455. The third small question requires omitting the mantissa after the tens of thousands of digits, which is sure to be recognized by everyone. The answer is 80,000. When writing, take "ten thousand" as the unit.
? But for many people, whether the result of the second question is "thousand" or "84,000", whether the first question is "hundred" or not, and the answer is "84,500" is hesitant.
? First of all, the unit of "ten thousand" and "100,000,000" originated from the inherent tradition of our nation, which is also emphasized in the Curriculum Standard 2065,438+065,438+0 Edition, and it is pointed out in the Content Standard that "large numbers will be1" Although the five editions of People's Education Edition, Jiangsu Education Edition, Beijing Normal University Edition, Zhejiang Education Edition and Xi Shi Normal University Edition are slightly different in order, they all point to the inherent system of tens of thousands and hundreds of millions in China. It can be seen that teachers are accustomed to using "10,000" and "100 million" as units, but not "100" and "1000" as units. This is due to China's own historical origin, the curriculum standards we follow and the teaching materials we teach.
However, it should be noted that the "three-position segmentation method" is also introduced in many teaching materials, precisely because the international unit of measurement is "thousand". In fact, when studying measurement units, our textbooks have long accepted "thousands" as the unit, and teachers and students of "kilometers" and "kilograms" are also skilled in using them without any obstacles, which shows that we can completely accept "thousands" and "hundreds" as the digital units.
? Secondly, it can be seen that if students can naturally realize that "hundred", "thousand" and "ten thousand" can be used as counting units, "65438+ ten thousand" is actually "1 ten thousand" and "1 ten thousand" can also be said as "1Qian Qian", but Professor Zhang Dianzhou pointed out in the book The Great Truth in Primary School Mathematics Textbooks that "it is absolutely necessary for a math teacher to introduce it from the perspective of mathematical culture, not just knowing that' 10,000' should be pronounced as' 10,000' in English class."
Teachers expect our teaching to be comprehensive, which is a good opportunity to break through the barriers between "number unit" and "long unit", "quality unit" and "quantity unit". Why should we be afraid and miss it?
? Third, in our culture, we can actually find examples in units of "hundred" and "thousand". The ancient army was composed of five men, twenty men, hundreds of centurions, five hundred small viceroy, one thousand big viceroy, three thousand positive and partial generals, five thousand positive and partial generals and ten thousand positive and deputy generals. In such a "head count", "hundred" and "thousand" are very good units.