Current location - Training Enrollment Network - Mathematics courses - Two-digit vertical calculation
Two-digit vertical calculation
Same digit alignment: addition: if the sum exceeds 10, move forward1; Subtraction: If it is not enough, borrow 1 from the previous one as10; Multiplication: Multiply every bit of the first factor by every bit of the second factor, and then add the results.

1, additive vertical calculation method

Digital alignment: digital to digital, digital to digital, plus sign moves forward. Calculation starts with numbers, numbers are added, numbers are written in numbers, and numbers are written in numbers. If the sum exceeds 10, move forward 1.

2. Subtractive vertical calculation method

Digital alignment: digital to digital, digital to digital, negative sign moving forward. The calculation starts with the number, and the number is subtracted, and the number is written as a number, and the number is subtracted from the number, and the number is written as a number. If it is not enough, borrow 1 from the last digit as 10.

3. Multiplication vertical calculation method

The same numbers are aligned. Starting with one digit, multiply each digit of the first factor by each digit of the second factor, and then add the results. Pay attention to the alignment of the same numbers.

Mathematical algorithm

1, addition algorithm

Additive commutative law: When two numbers are added, the position of the addend is exchanged, and the sum is unchanged, that is, A+B = B+A. The law of addition and association: when two numbers are added, the first two numbers are added first, and then the third number is added; Or add the last two numbers first, and then add the first number, and their sum is unchanged, that is, (a+b)+C=a+(b+c).

2. Law of multiplication operation

Multiplication and exchange law: when two numbers are multiplied, the position of the exchange factor remains unchanged, that is, axb=bxa. Multiplication and association law: when three numbers are multiplied, the first two numbers are multiplied, and then the third number is multiplied; Or the last two numbers are multiplied by the first number, and their products are unchanged, that is, (axb)xc=ax(bxc).

3. Law of subtraction operation

Law of subtraction operation: If several numbers are subtracted from a number continuously, the sum of all subtractions can be subtracted from this number, and the difference remains unchanged, that is, a-b-c=a-(b+c).

4. Division algorithm

There is no algorithm for division, because division is generally converted into multiplication, so multiplication algorithm can be used. The nature of division: quotient invariance: the dividend and divisor expand or shrink by the same multiple at the same time, and the quotient remains unchanged except 0; Removing two numbers in succession is equal to removing the product of these two numbers. a \b \c = a \b×c .