How can 348 163 242 537 be calculated?

Method 1: Symbolic moving.

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 signs".

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

Method 2: Combine the Law.

a) Bracketed method.

1.When adding parentheses to addition and subtraction operations, the parentheses are preceded by a plus sign, the parentheses are unchanged, the parentheses are preceded by a minus sign, and the parentheses are changed.

2.When adding parentheses to the multiplication and division operation, the parentheses are preceded by the multiplication sign, the parentheses are unchanged, the parentheses are preceded by the division sign, and the parentheses are changed by the sign.

b) De-bracket method.

1.When removing parentheses in addition and subtraction operations, the parentheses are preceded by the plus sign, the parentheses are removed and the parentheses are unchanged, and the parentheses are preceded by the minus sign, and the parentheses are removed to change the sign (the original addition in the parentheses is now to be subtracted; It used to be subtracting, but now it is going to be added. ）。

2.When removing parentheses in the multiplication and division operation, the parentheses are preceded by the multiplication sign, the parentheses are removed and the invariant sign is removed, and the division sign is preceded by the parentheses. It used to be dividing, but now it is going to be multiplied. ）。

Method 3: Multiplication of the law of distribution.

1.Distributive method.

In parentheses is an addition or subtraction operation, multiplying with another number, pay attention to the distribution.

Example: 8 (3+7).

2.Extract the common factor.

Note the extraction of the same factor.

Example: 9 8+9 2

3.Pay attention to the construction so that the equation satisfies the conditions of the multiplicative distributive property.

Example: 8 99

Method 4: Rounding method.

When you see the name, you know what this method means. When using this method, you need to pay attention to observation and find patterns. You should also pay attention to repayment, there is borrowing and repaying, and it is not difficult to borrow again.

Example: 9999+999+99+9

Method 5: Splitting method.

The splitting method is to split a number into several numbers for the convenience of calculation. This requires mastering some "good friends" such as: 2 and 5, 4 and 5, 4 and 25, 8 and 125, etc. Be careful not to change the size of the number in the split.

Example: 32 125 25

Method 6: Clever division into multiplication.

Dividing by a number is equal to multiplying by the reciprocal of this number.

Method 7: Split term method.

Fractional splitting refers to splitting the terms in the fractional equation so that the split items can be offset before and after, and this splitting calculation is called splitting method. A common method of splitting a number into the sum or difference of two or more numeric units.

This problem can be simplified using the associative law of addition.

348 163 242 537 How to count simply.

Method calculation letter formula: a+b=b+a

Example (short-term calculation process): 6+18= 18+6=24

Associative law of addition.

Adding the first two numbers, or adding the last two numbers first, and the invariant is called the additive associative law.

Letter formula: a+b+c=a+(b+c).

Example (short-term calculation process): 6+18+2= 6+(18+2)= 6+20= 26

The commutative law of addition a+b=b+aAdditive associative law a+b+c=a+(b+c)The commutative law of multiplication a*b=b*aMultiplicative associative a*b*c=a*(b*c) multiplicative distributive a*(b+c).

Take a look at the simple calculation below.

1) Use the commutative and associative properties of addition to calculate. Students are required to be good at observing the problem and have a sense of neatness. Such as: , etc.

2) Use the commutative and associative laws of multiplication to make simple calculations. If you encounter division, the same applies, or change the division to multiplication.

3) Use the multiplicative distributive law to perform simple calculations, and when encountering a division by a number, it is first reduced to the reciprocal of multiplying a number, and then distributed. It should also be noted that some of the problems are simplified using the inverse of the distributive property: i.e., extracting the common factor.

4) Use the nature of subtraction to make a simple calculation. The nature of subtraction is expressed by a letter formula: a b c = a (b + c), while paying attention to the reverse progression.

5) Use the nature of division to make simple calculations. The nature of division is expressed by a letter formula as follows: a b c = a (b c) while paying attention to the reverse progression.

6) The operation of numbers close to whole hundreds. This type of question requires the cooperation of skills such as splitting and conversion.

7) Observe an operation that is 0 or 1.

To solve such a question, you need to observe the formula, and it can be simple to make it ten rounds. After observation, it can be clearly seen that the simple sale between numbers and numbers is calculated by the Guanzhen Ant system.

Before and after the division sign, it can be approximated:

351 27 10 351 13

117 9 dec. 27

39 3 dec. 2713 dec. 27

Summary. 256 479) 35 Simple arithmetic.

Simple arithmetic: (256+479) 35=(256+444+35) 35=(700+35) 35=700 35+35 35=21

Dear, this is a little clearer.

Roger, thank you.

You are welcome.

Summary. 231 354 131 246 How to calculate easily.

The simple calculation method is as follows, you can refer to it, if you don't understand something, you can ask me, dear.

The simple calculation is to use the method of making up tens. Namely.

Calculate through a mobile phone calculator. Hope it helps.

Summary. Hello dear! Division first: 128 6 = 2 decimal places reserved) 324 156 128 6 easy way.

Hello dear! Division first: 128 6 = two decimal places reserved) Substitute this result into the original formula: 324 156 Answer: