Primary Mathematics Calculation Formulas, Elementary Mathematics Calculation Methods

Actual length = 2 cm * 200 = 4 meters.

Actual width = cm * 200 = 3 meters.

Actual area = 3 * 4 = 12 square meters.

1. Divide the distance (length) on the diagram by the scale bar to equal the actual distance (length).

2 (1 200) = 400 (cm) = 4 (m) 2, in the same way, divide the distance (width) on the figure by the scale bar to equal the actual distance (width):

cm) = 3 (m).

3. Multiply the actual length by the actual width to equal the actual area

4*3=12 (square meters).

A: (omitted).

The actual length is. 2 1 200 400 (cm) 4 (m) The actual width is. cm) = 3 (m).

The actual area is.

4*3=12 (square meters).

Solution: The actual length of the rectangular flower bed is xcm

2：x=1：200

x=2*200

x=400400cm=4m

Solution: The actual width of the rectangular flower bed is ycm

x=1:200

x=x=300300cm=3m

A: The actual area is 12

Solution: The actual distance of the length is x centimeters.

2：x=1：200

1x=2×200

x = 400,400 cm = 4 meters.

Solution: The actual distance of the set width is x centimeters.

x=1：200

1x=x=300,300 cm=3 meters.

3 4 = 12 square meters.

2cm is the actual 400cm = 4m, and the actual 150cm =

s=a*b=4*sqm.

The primary school math calculation method is as follows:

1. Multiplication operation per copy number of copies total number of copies of the total number of copies of the total number of copies of the number of copies of the number of copies per copy.

2. Multiples are calculated as 1 multiple, multiples, multi

3. Distance calculation speed time distance speed speed time distance speed time distance speed.

4. **Calculate the unit price, the quantity, the total price, the unit price, the total price, the total price, the quantity, the unit price.

5. Efficiency: Calculate work efficiency, working hours, total work, total work, working hours, total working hours, working hours, work efficiency.

6. Addition calculates the addition of the addition of the sum and the addition of one addition and the addition of the other.

7. Subtraction calculates the subtracted difference subtracted difference subtracted difference subtracted subtracted number.

8. Multiplication Problem Factor Factor Product One Factor Another Factor.

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.

Sometimes the associative law of addition is used, such as a+b+c, b and c are complements to each other, you can combine b and c, and then fight with a. If we change the above equation to x, we can easily calculate it by using the associative property of multiplication.

Set up x rooms originally planned to be produced in September.

1+20%)x-3/8x-(1-3/8)x*2/3=551.(1+20%)x: Originally planned for production.

Three-eighths of the month's production schedule.

3.(1-3 8) x*2 3: The remaining two-thirds are completed in the middle of the year; In the second half of the year, 550,000 pieces were completed.

It's because there are many plans, so it's more in 55.

Total production of goods: (840 + 60) (1-1 3-2 5) = 3375 If you use the equation to solve, let this batch of goods have x.

Then 1 3 x + 840 + 2 5 x = x + 60 is solved: x = 3375.

Solution: Let the thick one be the yuan, and the thin one will be the yuan.

x=12*x=10

7 jiao 5 points = yuan.

4 jiao 5 points = yuan.

Thick and thin. The sixth grade of elementary school will be in proportion.

Solution: Suppose you buy an exercise book x book, x<=6

Then the pencil bought a total of (, because (is an integer, so x=5, that is, the pencil bought a total of branches.

A: I bought 2 pencils and 5 exercise books.

Because a total of 5 yuan = 50 jiao, which is a multiple of 5.

So it doesn't matter how many pencils you buy.

The number of exercise books to buy must also be multiples of 5 in order to make the sum of 2 numbers a multiple of 5, which is also known to buy 5 exercise books.

Pencil: (50-5*8) 5=2 copies.

I bought 5 exercise books and 2 pencils.

A total of 5 yuan was spent, which is 50 jiao, because 50 is a multiple of 5, so the money spent to buy a pencil and the money spent to buy an exercise book are both multiples of 5. The common multiple of 5 and 8 within 50 is 40, so I bought 5 exercise books and 2 pencils.

Solution: 500 grams is kilograms.

2, that is, 4 yuan per kilogram of bananas.

3 4 = 12, that is, 3 kg of bananas sell for 12 yuan.

Isn't three kilograms just 3000 grams?

3000 grams is 6 times more than 500 grams.

It cost six times as much money.

2 times (3000 500) = 12

This should be understood.

3kg=3000g

2 500 = yuan per gram of bananas.

3000g banana is 3000 yuan.

Unit price = total** weight = 2 yuan 500 grams = yuan grams.

**= Unit price * weight = yuan gram * 3000 grams = 12 yuan.

It's hard for me, I forgot about elementary school. It really gave me a chance to reminisce hehe.

The question is how many 500 grams are in 3 kilograms.

3 kg = 3000 grams;

3000 500 = 6 (pcs).

So there should be.

2*6=12 (yuan).

=[2*6 is not 6 2 ask him].

The least common multiple of 2*3*5 60

Because it is a three-digit number and should be the smallest, it is 60*2 120

Therefore, the ** code of the laughing family is 5323120

The least common multiple of 2,3,5 is 30, and if the seven-digit number is 5323abc, then c 0 is 5323ab divisible by 3, that is, 1+a+b is an integer multiple of 3 and 1+a+b is less than 20, that is, a+b<20, a+b=3n-1 (n is a positive integer).

To take the smallest number, then n = 1, i.e. a+b 2 and a5323020

If it is a common multiple of 2,3,5, it must be a multiple of 30.

Here, 5,323,000 divided by 30 is 177433 remainder of 10, and to make it a multiple of 30, you have to add 20

So the ** number is 5323020

The last digit should be 0

The first four digits are about three, leaving 7, 7 + 2 = 9 is a multiple of three, and the last two digits add up to 2, which is the smallest number.

Isn't this a trick? Obviously, you can see at a glance that the last three digits are 235 I really don't know how to express it with an arithmetic

The smallest common multiple is 30

Can be composed of three digits 30 4 = 120

So the ** number of Xiaoxiaojia is 5323120

120？I don't know if it's right, I'm using 2x3x5=30

Again, it is a multiples of 30, and the smallest three digits are 120.

** number is 5323110, by the title, the smallest number of multiples of 2, 5 so it can be determined that the last digit is 0, the sum of 7 digits added must be a multiple of 3, so 5 + 3 + 2 + 3 + 1 + 1 = 15,

The first question, if there are n people in the class, then the passing person is 3 4n people, the failing 1 4n person has a total score of 70n points, and the total passing score is 80*3 4n=60n points, then the total score of the failing person is 70n-60n=10n10n (1 4n)=40 points.

The second question is marked with an x

Then you can get 43 * 43 x 37 x 43x, 43 * 43 37x, according to the first half, according to the same method, you can get x

To sum up, x can be five numbers.

It's so hard...