The similarity is that a number minus several numbers in a row equals this number minus the sum of these numbers. A number divided by several numbers in succession is equal to this number divided by the product of these numbers.

In addition, after using parentheses, the symbols inside will change.

For example:

3÷4÷5=3÷(4×5)?

3-4-5=3-(4+5)

A simple algorithm for continuous subtraction of a ÷ b ÷ c = a ÷ (b ⅹ c) is to subtract the sum of two numbers from one number, and a-b-c = a-(b+c) is represented by letters.

Operational nature of the Division:

1. The dividend is enlarged (reduced) by n times, and if the divisor remains the same, the quotient is correspondingly enlarged (reduced) by n times.

2. The divisor is expanded (reduced) by n times, while the dividend is unchanged, and the quotient is correspondingly reduced (expanded) by n times.

3. The nature of division: dividing the dividend by two divisors is equal to dividing by the product of these two divisors. Sometimes simple operations can be performed according to the nature of the division.

For example: 300 ÷ 25 ÷ 4 = 300 ÷ (25× 4) = 300 ÷100 = 3.