Appendix is one of the mathematical terms. In the addition formula, the two numbers added are called addends. The sum of several identical addends forms a multiplication. If one addend is 0, its sum is equal to the other addend itself. Adding a number is equal to subtracting the reciprocal of this number. One addend equals and subtracts another addend. This is the concept of additive nature. There are two addends in the addition formula, that is, the two numbers to the left of the equal sign. The other is sum, on the right side of the equal sign. This is a combination of two addends.

In the addition formula composed of two addends and summation, the lower grades directly fill the numbers with the addition formula. In middle school, the number of digits has developed from one digit to two digits to multiple digits. Because it is impossible to calculate by mouth, the concept of addition must be used. If the sum of two addends and one of them is known, the calculation of the other addend is based on the calculation method that one addend equals and subtracts the other addend.

Appendix+Appendix = and one addend = and+another addend.

Minus-Minus = difference.

Subtraction = minuend-difference.

Minus = Minus+Difference.

Factor × factor = product.

One factor = product ÷ another factor.

Dividend = quotient.

Divider = dividend quotient.

Dividend = quotient × divisor.

Division with remainder: dividend = quotient × divisor+remainder.

A number is divided by two consecutive numbers. You can multiply the last two numbers first and then divide this number by their product.

The result is the same. Example: 90 ÷ 5 ÷ 6 = 90 ÷ (5× 6).