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Anonymous users2024-02-11Take advantage of the laws of arithmetic. The commutative and associative properties of addition, and the commutative, associative, and distributive properties of multiplication, can be used to make calculations easier.
Decomposition factor. Some special numbers can be multiplied to get integers, such as harmony, and 8, etc., when we encounter these numbers, we can find a way to turn them into numbers that can get integers.
Digital distortion. Some of the numbers in the column formula can't be used in the easy way, but we can use the easy way after deforming some numbers, and then we have to deform the numbers.
Arithmetic progression. In some cases, the difference between adjacent numbers is the same, so we can use the equation of the equal difference series.
Numbers. In some equations, some numbers are the same, but the formula is relatively long, so we can set the equation composed of the same number as a letter, and then replace the corresponding number in the formula with a letter, and then calculate, which is much simpler.
Rounding method. Some decimals are very different from integers, and they have regularities, which we can make up whole numbers to calculate.
Subtraction properties: subtracting several numbers in a row is equal to subtracting the sum of these numbers.
Division properties: Dividing by several numbers in a row is equal to dividing by the product of those numbers.
Add the number in parentheses: Remove the parentheses (the invariant sign after it).
Subtract the number in parentheses: After removing the parentheses, the following numbers must be changed to symbols (addition, subtraction, subtraction, and addition).
Multiply the number in parentheses: Remove the parentheses (the invariant sign after it).
Divide by the number in parentheses: After removing the parentheses, the following numbers must be changed to a sign (multiply, divide, divide).
Types of Easy Methods:
Multiply several numbers, there are 25 with 4 or 125 with 8: apply the multiplicative commutative or multiplicative associative law.
25 and 4 or 125 and 8 can be multiplied first.
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Anonymous users2024-02-10For the fifth grade, the simple decimal formula is used as an example, and the simple method is as follows:
Commutative laws of addition and multiplication. It illustrates that one can exchange the order of the elements in addition or multiplication. The third is the associative law of addition.
It shows that when three numbers are added, or we add the first to the sum of the second and third; Or we add the sum of the first and second to the third and the result is the same.
The fourth is the associative law of the multiplication of the orange brigade. The last one is the distributive law, which shows that when multiplying an integer by a sum, we can use this whole number to multiply each term of the sum, and then add up the products.
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Anonymous users2024-02-09Easy calculation:Solution: Adopt the splitting method:
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Simple calculation is a special kind of calculation, which uses the laws of operation and the basic properties of numbers, so as to make the calculation easy, so that a very complex formula becomes easy to calculate the number.
Easy calculations with laws:
1. Multiplicative distributive property:
The most common method used in simple calculations is the multiplicative distributive property. The multiplicative distributive property refers to ax(b+c) = axb+axc, where a, b, c are arbitrary real numbers. Conversely, AXB+AXC=AX(B+C) is called the inverse of the multiplicative distributive law (also known as extracting the common divisor), especially when a and b complement each other, this method is more useful.
There are also times when the associative property of addition is used, such as a+b+c, where b and c are complements to each other, so you can combine b and c and multiply it with a. If the + in the above equation is changed to x, it can also be easily calculated by combining multiplication with the law auspicious crack.
2. Multiplicative associative law:
The associative law of multiplication is also a method of doing simple operations, which is expressed by letters as (a b) c = a (b c), and its definition (method) is: multiply three numbers, first multiply the first two numbers, and then multiply the third number; Or multiply the last two numbers first, and then multiply them with the first number, and the product remains the same. It can change the order of operations in multiplication operations, and in daily life, the users of the multiplication law are not very tolerant, mainly in some more complex operations to play a simple role.
3. Multiplicative commutative law:
The commutative property of multiplication is used to invert the positions of individual numbers: a b = b a.
4. The commutative law of addition:
The commutative property of addition is used to invert the positions of individual numbers: a+b=b+a.
5. Addition associative law:
a+b）+c=a+（b+c）。
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Anonymous users2024-02-08The fifth grade decimal is simply calculated as follows: Sail Yinbu
22, state spike (
43, Bo Hu.
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Anonymous users2024-02-07Simple decimal arithmetic.
1. Signed moving method (according to: addition commutative law and multiplicative commutative rate).
When a calculation problem has only the same level of operations (only multiplication and division or only addition and subtraction) and no parentheses, we can "move with symbols".
a+b+c=a+c+b,a+b-c=a-c+b,a-b+c=a+c-b,a-b-c=a-c-b;a×b×c=a×c×b,a÷b÷c=a÷c÷b,a×b÷c=a÷c×b,a÷b×c=a×c÷b)
2. Binding the Law.
a) Bracketed method.
1.When a calculation problem has only addition and subtraction operations and no parentheses, we can answer by adding brackets directly after the plus sign to brackets.
The operation in the number turned out to be addition or addition, subtraction or subtraction. However, when parentheses are added after the minus sign, the operation enclosed in the parentheses is Qingchun Zheng, which was originally an addition, and now it will become a subtraction; It used to be subtracting, but now it is going to be added. (i.e., parentheses are added to addition and subtraction.)
It is preceded by a plus sign, the parentheses are unchanged, the parentheses are preceded by a minus sign, and the parentheses are changed. ）
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Fraction addition and subtraction calculations are as follows:
In the past year, the children have made comparative improvements in the mastery of learning methods; Significant improvement in academic performance; The hands-on ability has been strengthened, the children's sense of responsibility and social responsibility has been strengthened, and the knowledge of various subjects has been expanded relatively well, and the progress has been obvious; Physically and mentally healthy, mature and steady.
Uncle, sympathy, I'm also looking for it, but it still makes sense to write it yourself, how can you let others help you during your summer vacation? Work your own Don't be unhappy (give up) when you see me say something like this, come on, I also wrote it myself.
Hehe, I have my own understanding of raising children. Children are small, they can't understand the big truths, and small problems are not easy to change This is a common problem of all children, not a problem of a certain child. As parents, we can't beat or scold, because there is an old saying that children don't remember to eat. >>>More