99 85 Easy Ways? 2700 36 Easy Method?

Easy to calculate. It 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, and make a very complex formula easy to calculate the number.

1. Addition commutative law: the position of two numbers is added and the sum is unchanged.

2. Associative law of addition.

Add three numbers, add the first two numbers first, or add the last two numbers first, and then add them with the third number, and the sum is unchanged.

3. Multiplicative commutative law: when two numbers are multiplied, the position and product of the exchange factor remain unchanged.

4. Multiplication and associative law.

Multiply three numbers, multiply the first two numbers, or multiply the last two numbers first, and then multiply the third number, and their product remains the same.

5. Multiplicative distributive law.

If you multiply two numbers by the same number, you can multiply the two additives by the same number, and then add the two products together, and the result remains the same. For example: (2+4) 5 2 5+4 56.

The nature of division: In division, the dividend.

The quotient does not change if it expands (or shrinks) the same multiple at the same time as the divisor. o divided by any number that is not o gives o. Easy multiplication:

If there is an o at the end of the multiplier or multiplier, you can first multiply the front of o, and the zeros do not participate in the operation, and several zeros fall and are added to the end of the product.

99 85 Easy Ways?

Solution: Use the multiplicative distributive property to make the calculation easy:

Multiplicative distributive property:

The sum of two numbers is multiplied by one number, and they can be multiplied by this number respectively, and then added to get the same number, which is called the distributive law.

The letter indicates: (a+b) c=a c+b c

Variant: (a-b) c=a c-b c

Think of this equation as a fraction, with the numerator and denominator shrinking by a factor of 9 at the same time, becoming 2700 9 3600 9=300 4=75

Split 36 into 9 and 4 with 2700 have multiples of good simple calculations.

2227 23 I don't see how easy it is.

364 divided by 28 in a brief discussion with 13 times 28 divided by 28

1. Waiter section 364 28=13

Since there is only division and multiplication in this equation, there is no need to care about the order. There is no particularly easy way to do it, but to dismantle 364 and make a mess of 300+64

Pat the teaser with 4 minutes].

30800 9 raid only 7

Use your fingers to take 7 minutes].

The easy calculation process is as follows:

Hello, according to your question, this question should do this.

In this way, it is relatively simple to calculate 40 125 (100-1), but after taking the wheel, first calculate 40 125 = 5000, and then calculate 5000 100-5000 1, and the result is judged to be 495000

The simple algorithm for this question is auspicious: 40x(100-1)x25x5=40x25x5x(100-1)=5000x(100-1)=500000-5000=495000. Burn aside.

You are coarse and well, and the simple algorithm of this smart argument is 40x(100-1)x25x5=40x25x5x(100-1)=5000x(100-1)=500000-5000=495000.