Lead: The following is the handwritten newspaper content about the decimal point of mathematics that I carefully arranged for you. I hope it helps you. Welcome to reading.
Mathematical decimal point An inconspicuous decimal point in the middle of "123" will become "1.23" or "12.3". If you add an inconspicuous decimal point to "456", it will also become "4.56" or "45.6" ... The decimal point is such a magical symbol that all numbers can be "tiny"!
The first point: when the lines are vertical, the numbers should be aligned. When column multiplication is vertical, many students often mistakenly think that integers are aligned with integers and decimals are aligned with decimals. If you do that, it's all wet! The correct method should be this: No matter where the decimal point is, when the column is vertical, the ends of the two numbers must be aligned. Only the results and answers calculated in this way are correct!
The second point: Never point the decimal point in the process of vertical column. This is a common problem of many students. When you click the decimal point in the exam, you will be deducted, and you will regret it!
Number three: Be careful. Multiply a decimal by 10, 100, 1000 ... or divide a decimal by 10, 100, 1000 ... Never make a mistake about the position and direction of the decimal point!
Mathematical decimal point handwritten newspaper content Part II Talking about decimal points, students all find it difficult. After learning the addition and subtraction of decimals, we have entered the learning hall of decimal multiplication and division, and have a new understanding of decimals.
To learn decimals, we should first understand several laws:
(1) When an integer is multiplied by a decimal below 1, the quotient becomes smaller, not larger;
(2) Multiplying a number by 0. 1 reduces the product by 10, multiplying the product by 0.0 1 reduces the product by 100, and so on;
(3) Don't mark the decimal point in the process of fractional division, and then choose a suitable position to mark the decimal point when the quotient comes out;
(4) The quotient of a number (except 0) divided by 0.5 is twice that of this number.
Mastering the above four laws, decimal multiplication and division can be easily solved. Learn multiplication calculation first, multiply two decimals, count how many digits there are in these two decimals, and finally, put the decimal point in front. Multiplication is simple, but division is difficult? In fact, they are all the same, so it is not difficult to master the regular operation of fractional division.
After learning the above knowledge, let's expand it. The question is this: when Xiao careless calculates a decimal multiplication operation, the product of two numbers is 180, and one factor is 0 1, so what is the other factor?
Let's look at the previous formula again: when a number is multiplied by 0. 1, the product will be reduced by 10, and it will be180 ÷ 0.1=1800. How simple.
Learning decimal multiplication and division is really interesting.
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