8 7x2 4 0 87x7 6 8 7 How do you subtract from it?

Clever calculation and problem solving ideas: four operation rules (calculation in order, first multiplication and division and then addition and subtraction, parentheses are calculated first brackets, and there are power first calculation of the multiplication) that is, the off-form operation (recursive equality calculation) needs to be carried out under the premise of this principle. Problem solving process:

Extended information: first align the last digit of the two multipliers, then use the second multiplier respectively, multiply a multiplier by each digit from the last digit, and finally add up the calculated result to be the product, if the multiplier is a decimal place, it can be expanded by the corresponding multiplier first, and finally the product is reduced by the corresponding multiple;

Problem solving: Step 1: 6 87=522

Step 2: 1 87 = 870

Step 3: 4 87 = 34800

According to the above calculation steps, the combined result is:

If you have any doubts, please ask and be satisfied.

Complement rounding.

For close integers in the equation.

10. A whole hundred ......by transforming it into a whole.

10. A whole hundred ......The number of numbers, in the form of adding or subtracting a number, can be easily calculated.

For example: 536-198 = 536 (200 2) = 536 200 + 2 = 338

44x101=44x（100+1）=44x100+44=44442.Decomposition method.

In some multiplication and division equations, you can break down a number of numbers to make the calculation easier.

For example: 3Benchmark number method.

If you add a number of numbers that are close to a certain number, you can use a certain number as the base number, and then multiply the base number by the number of added numbers, and add the difference between each number and the base number, and you can get the calculation result.

For example: 81+85+82+78+79

80x5+（1+5+2-2-1）

4.The splitting method is mainly to cancel out some fractions after splitting each other to achieve the purpose of simplifying the operation, and generally fractions in the form of 1 ax (a+1) can be split into. 1/a-1/a+1。

For example: 1 1x2+1 2x3+1 3x4+1 4x5+1 5x6

Like this formula, how to make a simple calculation? I think it's easier to give you an easy way to use it directly.

The answer is equal. Row cavity.

This problem can be calculated vertically, as shown in the figure below: Wax with Oak.

Solution: Both the dividend and the divisor are enlarged by a factor of 10).

This question is:

If you agree, please give it a thumbs up, thank you.

(9a(.)

You Liang is accompanied by grinding. Talking about stupidity.

How to transport the land: how to calculate it can (Wang Hood (etc.

Solution: Equal to (25 accusal).

Known demand is equal to talking more about the disadvantages and less about the shortcomings.

Answer: Equal to 25

25 (Yun Lu La, using multiplication to distribute the law of defeat in the bridge town) Sensitive trembling.

Method 1.

Fang Bei Ming Law II.

Alexandria imitates rotten sue + (

It is simple to calculate filial piety with the distribution rate of Qiaoxian Liang. Distribution.

A good classmate with oak limbs can be seen as 12.5 3, so this formula is seven point 6 2 point 5 + 2 point 5 2.4, in this way, there is one in front and behind can be put forward by Liang Shizhi posture, which is equal to.

。There is multiplication in the operation, there is addition, and the multiplication must be calculated first, and then the addition.

I hope I can help you dig out. Guess the core.

Wangcai sells imitation, thank you Zhongyan Fiber Jujube Sun.

Ten ode to the spring of the clear forest.

Ten years ago.

You are good, and the finch mill is silver=

Subtract the Zen crack?

Concealment. Thank you

Two know trembling ten.

Type 2 Collapse Fierce Circle 5x

Two-two, 19+6, two-25

Original = Ming Tong Ming.

Wheel (Agitation 10

Solution: Use the multiplication method to divide by dividing the rent by the sale of rent. Calculate the loss of trillions.