Why is the decimal point of decimal multiplication not aligned to 25

I think that when calculating decimal addition and subtraction, the essence of decimal point alignment is the same digit alignment. This is because numbers in different digits cannot be added or subtracted directly. When calculating decimal multiplication, we expand each factor accordingly according to the law of product change, so that it is converted from a small number to an integer, first multiply according to the integer multiplication, and finally deal with the decimal point problem in the product.

Therefore, when calculating decimal multiplication, the decimal point can be misaligned.

Our teacher will give a lecture in the open class tomorrow, so I must leave this recommended answer to me!!

Our teacher said that there is a special theorem for decimal multiplication in mathematics, as long as the numbers are aligned, even if the decimal points are not aligned, it is OK, but the numbers must be aligned! And aligning the decimal point will be miscalculated. Now for you to do some good multiplication of decimals.

You count the decimal number as an integer, and then add the decimal point at the end. Okay, let's get here first. If you feel that your problem has been solved, then give it a go. 3q。

The algorithm of decimal multiplication and integer multiplication should be the same, no decimal alignment is required, just need to calculate the result according to the algorithm of integer multiplication, and then count how many decimal places are after the decimal point, and add the decimal point to the result. There is no reason why the decimal point is not aligned, it is a rule.

Because the multiplication of decimal places evolved through integer multiplication, everyone sees them as integers, and finally finds the position of the decimal point, which is not easy to make mistakes.

Because the alignment is wrong, if the divisor is, the divisor should be enlarged by 10 times, if the dividend is, then the dividend should be enlarged by 10 times, and the decimal point of the number should be aligned with the decimal point of the dividend.

It's okay to align, it's okay not to align it, it's up to you.

<> decimal addition and subtraction decimal point should be aligned because the decimal point is preceded by an integer digit and followed by a decimal place.

There are four issues to pay attention to in multiplication vertical calculation:

1. The last digit of the two numbers should be aligned.

2. Try to write the numbers with more numbers on the top and the numbers with fewer numbers below to reduce the number of multiplications.

3. If there is a chaotic "0" at the end of the two numbers, you can only align the last digit of the number in front of the "0" when writing the vertical type, and finally add the number of acres of "0" common to the two numbers behind the vertical product.

4. Decimal multiplication should determine the position of the decimal point of the product according to the multiple of the decimal place.

The addition and subtraction of decimal numbers have the same requirements as the addition and subtraction of integers: the numbers of the same unit can be added and subtracted, that is, the same digits must be aligned.

When calculating the addition and subtraction of integers, as long as the last digit is aligned, that is, the single digit, the other digits are also aligned.

1. The last place of the decimal place is not fixed, and the last place of a decimal place may be the percentile, such as its last place is in the percentile, indicating 5 hundredths or one-thousandth), or it may be in the thousandth, such as the last place of this decimal place is in the thousandth place, indicating 5 thousandths).

2. If the two decimal places are added together, it is obviously not possible because their digits are not the same. If you align them to decimal places, the same digits will also be aligned, and the addition and subtraction of decimal places can be performed correctly.

3. From the vertical calculation, you can also see why the decimal points should be aligned. As can be seen from the vertical type, the decimal point is aligned, the ten digits are aligned with the tens, the single digits and the single digits, etc., that is, the same digits are aligned.

4. Why should the decimal point be aligned, because to ensure accuracy and accuracy, if the decimal point is not aligned, then for a string of numbers, there may be a kaleidoscopic result, then the outcome is very different, sometimes it will lead to a big mistake.

The decimal points of decimal multiplication do not need to be aligned, and when calculating decimal multiplication vertically, the decimal points of the two multipliers do not necessarily have to be aligned, as long as the last digit is aligned. Calculating decimal multiplication is based on the method of integer multiplication, first aligning the last digit of the multiplier, calculating the product according to the law of integer multiplication, and then seeing how many decimal places there are in the multiplier, count the number from the right side of the product, and point to the decimal point.

Vertical calculation refers to a vertical calculation in the calculation process to make the calculation simple. The same digits are aligned when the addition is calculated, and if the sum exceeds 10, it will be advanced by 1. When subtracting the calculation, the same digit pairs are all together, if it is not enough to subtract, then borrow 1 as 10 for the previous digit.

Vertical means that each transition number is changed by the previous transition number, the single digit of the previous transition number is multiplied by 2, if you need to carry the position, then advance to the front by 1, and then the single digit rises by ten to know the leakage and leakage, and so on, and the single digit is supplemented with a new search and training operation number.

No. Ignore the decimal point at first, and add the decimal point to the product from right to left (the total number of decimal places of the two decimal places) after multiplication.

For example, multiply, multiply 33 by 3 to get 99, and then count from right to left, adding a decimal point to the second place of 99, that is.

Expansion of the exhibition materials:

Add or remove any zero at the end of the decimal and keep the decimal in size. For example:. If you move the decimal point to the right (or left) by n digits, the value of the decimal will expand (or shrink) to the nth power of the base.

Multiplication principle: If the dependent variable f is ,.... with the independent variable x1, x2, x3If there is a direct proportional relationship between xn and each independent variable is qualitatively different, and the lack of any independent variable and dependent variable f loses its meaning, it is multiplication.

The same number can be aligned, in this case there is nothing wrong with alignment, but if it is not the same, do not need to align, just start counting from the right, and count to where the decimal point is.

Calculation tips for decimal multiplication:

When calculating decimal multiplication, you can first calculate the product according to the rules of integer multiplication, and then see how many decimal places there are in the factor, and count the number from the right side of the product, and point to the decimal point.

One thing to note about multiplication of decimal places is that the number of decimal places is added, for example:

The reason for the decimal point alignment in decimal division is to perform the calculation and ensure the correctness of the calculation result. Because embedding decimal numbers is a common form of real numbers, it represents some incomplete values, which contain not only integer parts, but also decimal parts. In decimal division calculations, we need to use the divisor and the dividend to perform the operation, and their decimal points need to be aligned to ensure the accuracy of the calculation.

If the divisor is not aligned with the decimal point of the dividend, then it will cause bias and errors in the calculation, resulting in inaccurate calculation results. For example, if we calculate that if we don't align the decimal point, i.e., write 1, then the result is.

For decimal division.

Generally, it is a hail celebration that requires a quotient to block the decimal point.

To be with the dividend.

Decimal point alignment.

The main purpose of this is to make it easy for the source to make mistakes.

After alignment.

Calculate which digit to divide to.

The quotient is written on which digit of the dividend is written.

Otherwise, you may be mistaken.

You don't need to align the decimal points when calculating multiplication, ignore the decimal point when you do the operation, and add the decimal point to the decimal point from right to left (the total number of decimal points of the two decimal places) after multiplication. Multiplication refers to a shortcut to add up the same numbers. The result is called the product, and "x" is the multiplier sign.

Add or remove any zero at the end of the decimal and keep the decimal in size. If the decimal spinal kernel modulus is shifted to the right (or left) by n digits, the value of the decimal will expand (or shrink) to the nth power of the base.

Multiplication principle: If the dependent variable f is ,.... with the independent variable x1, x2, x3, there is a direct proportional relationship between xn and each independent variable is qualitatively different, and the absence of any independent variable dependent variable f loses its meaning, then multiplication.