General Source of Computational Methods, Volume 2

The method of the Nine Returns original: Jiugui; a collective term for the abacus division tables for divisors 2 through 9 is for equalizing and partitioning,
The combinations of numbers have always been ready-made.
If the remainder is large enough, return it as a ten to the higher place,
If the division is not yet complete, carry the remainder to the next row.

How should a student approach the Nine Returns?
Push the divisor from the left head of the Dividend Dividend (shi); the total quantity being divided.
When a "carry" is triggered, you must advance the digit to the position above,
Then add to the next lower position to continue the operation.

Problem: Suppose there are 456.2 dan original: 四百五十六石二斗; a dan is a unit of volume, and a dou is one-tenth of a dan. Note: The math in the answer suggests the source text might have originally intended 486.2 dan of rice. If every one tael Tael (liang); a unit of silver currency weight of silver buys 2 dan of rice, ask: how much silver is required in total?

Answer: 243 taels and 1 mace original: 二百四十三両一錢; a mace or qian is one-tenth of a tael. 243.1 taels is the result of 486.2 divided by 2.

Method: Set the total rice as the Dividend (shi). Use the purchase rate of 2 dan per tael as the Divisor Divisor (fa); the number by which the dividend is divided. Apply the "Return" method specifically the "Two Returns" (Ergui) table: "Two: five-on-five," meaning 1 divided by 2 equals 0.5 to arrive at the answer.