Multi digit multiplication in primary school mathematics

The fast calculation method of multi digit multiplication is as follows:

1, more than ten times more than ten: Formula: head by head, tail by tail, tail by tail. Example: 12 × 14= Solution: 1 × 1=12＋4＝62 × 4＝812 × 14 = 168 note: if the number of digits is multiplied by each other, if the number is less than two digits, 0 should be used

2, the head is the same, the tail is complementary (the tail is equal to 10): Formula: after a head plus 1, the head multiplies the head, and the tail multiplies the tail. Example: 23 × 27= Solution: 2 + 1 = 32 × 3＝63 × 7＝2123 × 27 = 621 note: if the number of digits is multiplied by each other, if the number is less than two digits, 0 will be used

3. The first multiplier complements each other, and the other multiplier has the same number: Formula: after one head plus one, the head multiplies the head, and the tail multiplies the tail. Example: 37 × 44= Solution: 3 + 1 = 44 × 4=167 × 4=2837 × 44 = 1628 note: if the number of digits is multiplied by each other, if it is less than two digits, 0 will be used

5, 11 times any number: pithy formula: head and tail do not move down, the sum of the middle pull down. Example: 11 × 23125= Solution: 2 + 3 = 53 + 1 = 41 + 2 = 32 + 5 = 72 and 5 are at the beginning and end of 11, respectively × 23125 = 254375 note: with the full ten to enter one

multiplication principle:

if the dependent variable f is directly proportional to the independent variables x1, X2, X3,.... xn, and each independent variable is qualitatively different, without any independent variable, the dependent variable f will lose its meaning, it is multiplication

in probability theory, there are n steps for an event to proce results. The first step includes M1 different results, the second step includes M2 different results,..., and the nth step includes Mn different results. Then this event may appear n = M1 × M2 × M3 ×……× Mn is a different result

let a be m × The matrix of n

2、A' Ax=0 → x' A' Ax=0 → (Ax)' Ax = 0 → AX = 0

so the two equations have the same solution

MBR is the abbreviation of master boot record. In the traditional hard disk partition mode, the boot sector is the first sector of each partition, and the main boot sector is the first sector of the hard disk

in order to facilitate the computer to access the hard disk, the space on the hard disk is divided into many blocks (sectors in English), and then each block is assigned an address, which is called the logical block address (LBA)

in MBR, the size of partition table is fixed, which can hold four primary partition information. In the MBR partition table, logical block addresses are represented by 32-bit binary numbers, so a total of 2 ^ 32 logical block addresses can be represented. If a sector size is 512 bytes, the maximum partition capacity of MBR hard disk is only 2TB

extended data:

when starting the PC, the system first tests the hardware equipment, and then enters the bootstrap program int 19h after the test is successful, and then reads the main boot record (MBR) contents of 0 cylinder, 0 head and 1 sector of the system disk to the area where the address of the specified memory unit 0:7c00 starts, and executes the MBR program segment

1

2. Find the bootable "active" partition in the partition table

1. The men and women of the secret service received the task of pretending to be tourists and tracking the illegal trade in a shopping mall
but the shopping mall is in another space. What if you can't get there? In a beach, put on VR glasses, you can go shopping
when shopping, you can get the goods in another space by using the transfer box and extending your hand in. Once the gun goes in, it can fight with people in another space{ RRRRR}

There are more than 2000 Star City film proction team from 25 different countries, including 10 Chinese

Wu Yifan took part in the film. Unknown role name

on May 15, 2014, Wu Yifan formally applied to Seoul Central District Court for ruling that the exclusive contract with SM Entertainment company was invalid. After that, Wu Yifan returned to China for development, starring in his first film and the leading role of Xu Jinglei's film "there is a place only we know", which won the best new actor award at the 3rd London International Chinese Film Festival

vogue in July 2015. In the same year, the first original proction single "bad girl" was released and won the most popular newcomer of the year in the 6th Global pop music golden list and the most influential male singer of the year in the new Asian music list. At the end of the year, the starring film "old cannon" was released, and it was further widely concerned because of its role as little master Tan Xiaofei

in January 2016, burberry was on the Burberry show for its 160th anniversary. In the same year, he served as the global spokesperson of Burberry Chinese. Then ray ban and Bvlgari announced that they were spokesmen one after another, so they became the first Chinese star to hold a number of luxury goods in hand. In July, the box office of the starring film "you are still here" totaled 337 million, setting a record for youth films of the same year. In August, the starring film "summer has arbor" was released. With a total pre-sale of more than 36 million yuan, it won the top spot in the same theme films. In four days, the box office accumulated more than 100 million yuan and won the golden crane Award for best actor at the Japan China Film Festival. The first English single July was released in November [14-20]

in February 2017, the box office of the starring film "journey to the west to sube demons" exceeded 1.6 billion, in which Wu Yifan played Tang Sanzang [21]. In the same month, he was invited to the 59th Grammy Awards ceremony [13]

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