What is the explanation of 625?

Modern Chinese dictionaries interpret "Yi tui (tui) 625" as: this is a formula for calculating the weight with an abacus, and 1 divided by 16 is 0.0625, so as to shirk cleanliness. Retreat is the homonym of "push", sometimes it is also called "push".

From Ouyang Shan's "San Fang": "The Chen family, old and young, is just a retreat, saying that their businessmen never make friends with the government, and they push it clean!"

Operation sequence of four operations:

1. If there is only addition and subtraction or only multiplication and division, it is calculated from left to right.

2. If primary operation and secondary operation exist at the same time, the secondary operation is calculated first.

3. If there are primary, secondary and tertiary operations (i.e. power, root and logarithm operations) at the same time, first calculate the tertiary operation, and then calculate the other two levels.

4. If there are brackets, count the numbers in brackets first (no matter what level, count first).

5. The third level should be counted in brackets, and then the second and first levels should be counted.