3.56+4.54+6.44+5.46,5.03-0.25- 1.754.86+5.24- 1.86,8. 13+( 1.87-0.5)23.7- 1.6-3.7-8.4,87.4-(2 1.25+ 17.4)-8.75.
1, decimal addition calculation:
When adding two decimal places, first align the decimal points, then add them bit by bit, and finally keep the number with the same number after the decimal point.
2. Decimal subtraction calculation:
When subtracting two decimal places, first align the decimal points, then subtract by digits, and finally keep the number with the same number of digits after the decimal point.
3, decimal multiplication calculation:
When multiplying two decimal places, directly multiply the numbers before and after the decimal point, and then determine the decimal point position of the final result.
4. Calculation of fractional division:
When two decimals are divided, the divisor and dividend are first converted into integers, then the integers are divided, and finally the decimal point position of the final result is determined.
5. Decimal percentage calculation:
When converting percentages into decimals, remove the percent sign and divide by 100. When converting a decimal to a percentage, you need to multiply it by 100 and add a percent sign.
6. Comparison size of decimals:
When comparing the sizes of two decimals, first align the decimal points and compare them bit by bit from left to right. If one digit is different, the size relationship can be determined.
7. Decimal rounding:
Judging the size of the number of digits to be discarded in the last digit according to the number of digits to be reserved, and carrying if it is greater than or equal to 5; Otherwise give up.
8. Decimal rounding and rounding:
In the case of carry, add decimal places to the corresponding digits after the decimal point; In the case of rounding, the number after the decimal point is rounded directly.
9, decimal simplification:
When converting decimals into fractions, you can take the decimal part as the numerator, the power of 10 of the decimal place as the denominator, and then divide it to get the simplest fraction.
10 and approximate calculation of decimals;
When the decimals are long or need to be estimated, the decimals can be appropriately reduced and calculated with approximate values to improve the calculation efficiency.
1 1, fractional part extraction:
The decimal part of the decimal can be obtained by removing the integer part of the decimal.
12, decimal cycle decimal representation:
When there is an infinite cycle in the decimal part, you can use the ellipsis line to draw a horizontal line above the cycle part to indicate the cycle.
13, reciprocal of decimal:
By reversing the sign of a decimal number, you can get its reciprocal.
14, decimal square calculation:
First, the decimal is converted into decimal form, then the square operation is carried out, and finally the result is converted into decimal form.
15, root calculation of decimal:
First, the decimal is converted into decimal form, then the root is calculated, and finally the result is converted into decimal form.
16, decimal power calculation:
First, the decimal is converted into decimal form, then the power operation is carried out, and finally the result is converted into decimal form.
17, decimal and other decimal conversion:
Decimals can be converted into other decimals or other decimals can be converted into decimals by division or multiplication.
18, addition and multiplication of decimals:
You can add or multiply decimals many times in a circular or recursive way to get the result of addition or multiplication.
19, average calculation of decimals:
Add up multiple decimals and then divide by the number of decimal places to get the average.
20, decimal adjustment and standardization:
According to the need, the decimal number is rounded, refined or formatted to meet the requirements of practical application.
Mathematical algorithm of 2 1, decimal;
The mathematical operation of decimals follows the basic laws such as additive commutative law, the law of addition and association, the law of multiplication and exchange, and the law of multiplication and association.
22, decimal scientific notation said:
When the decimal number is larger or smaller, it can be expressed by scientific counting method, in which the exponential part indicates the displacement of the decimal point.
23, decimal notation regulations:
The sign of the decimal is determined by the decimal part, that is, the decimal part is regular, the decimal part is positive and the decimal part is negative.
24, decimal common mistakes and solutions:
Common decimal calculation errors include decimal dislocation and decimal calculation errors, which can be solved through careful inspection and verification.
25. Application fields of decimals:
Decimals are widely used in finance, science, engineering and other fields, and can be used to express accurate measurement results or perform complex calculations.
26, decimal calculator tools:
Modern calculator has the function of decimal calculation, which can conveniently and quickly perform various decimal operations and improve the calculation efficiency.
27, decimal knowledge expansion:
Knowing more about decimals, such as their cyclic nature and irrational numbers, can further explore the mysteries of mathematics.